Sapiens Dominabitur Astris: A Diachronic Survey of a Ubiquitous Astrological Phrase

Abstract

From the late thirteenth through late seventeenth centuries, a single three-word Latin phrase—sapiens dominabitur astris, or “the wise man will be master of the stars”—proliferated in astrological, theological, philosophical, and literary texts. It became a convenient marker denoting orthodox positions on free will and defining the boundaries of the scientifically and morally legitimate practice of astrology. By combining the methodology of a diachronic historical survey with a microhistorical focus on evolving phraseology, this study argues that closely examining the use of this phrase reveals how debates about the meanings of wisdom, free will, determinism, and the interpretation of stellar influence on human events changed radically across four centuries of Western European cultural and intellectual history. The first half of this article charts the scholastic response to theological criticisms of astrology and the reconciliation of Aristotelian-Ptolemaic cosmology with Catholic theology, paying special attention to its implications for astrology as viewed through scholarly uses of the phrase. The second half of the article shows how the phrase developed a multitude of idiosyncratic meanings in the sixteenth and seventeenth centuries, fracturing its late medieval scholastic unity, as new forms of philosophical, socio-political, religious, and scientific critiques upended astrological beliefs and practices. Ultimately, this paper argues that examining the theory and praxis of astrology through the changing phraseological meanings of “sapiens dominabitur astris” allows historians and cultural anthropologists to better discern the dialectical (as opposed to binary) relationships between free will and determinism in the West.

1. Introduction

In the late thirteenth century, astrologers began to use a pithy aphorism, often apocryphally attributed to second-century polymath Claudius Ptolemy, as a defense against astrology’s critics: “sapiens dominabitur astris” or “the wise man will be master of the stars” (Tester 1987, p. 177; Kieckhefer 2000, p. 129).1 In these earliest uses, astrologers asserted that the stars neither compelled peoples’ actions nor controlled their destinies, and indeed, for the prudent individual, precisely the opposite held true. Rather than succumbing to a future the stars had predetermined, the “wise man” was an astrologically literate person armed with the foreknowledge to challenge and subvert that fate. The context in which astrologers and their defenders employed the phrase from the late thirteenth through late seventeenth centuries reveals much about the place at which the they divided the legitimate aspects of astrology from the illegitimate ones (Lindberg 1992, p. 274; Thorndike 1934; Flint 1991, esp. pp. 100–50).

Exactly who was the “wise man” and what aspect of the stars should he hope to master? The answer is more complicated than a simple, literal reading of the phrase might suggest. To some, the phrase suggested the need for methodological mastery of astrological techniques while for others it demanded strict allegiance to orthodox Christian positions on free will prior to attempting any astrological prediction. Some used it to justify why medicine, agriculture, and weather prediction—largely uncontroversial aspects of astrology with little bearing on free will—required knowledge of stars. Others used it to defend more controversial practices like drawing natal charts to predict an individual’s death. The use of the phrase “sapiens dominabitur astris” tempered the impact astrology had on its theologically and philosophically skeptical critics, and it can be read as a barometer to determine the always morphing intellectual, cultural, and religious positions on astrology during its late medieval and Renaissance heyday.

Tracking the use of the phrase “sapiens dominabitur astris” and its evolving interpretations from its first appearance in the mid- to late thirteenth century to the decline of astrology as a science in the seventeenth suggests a myriad of ways that astrological disputes influenced broader debates over seemingly oppositional forces like free will and determinism, science and superstition, reason and the irrational, pagan and Christian, and Catholic and Protestant within the broader culture of Western European Christendom. It would be a mistake, however, to view any of these debates as binary or to view the definitions of those categories as static. Free will and determinism especially, in both Christian and astrological contexts, existed on a spectrum rather than as polarities. The way astrologers and their defenders deployed the phrase “sapiens dominabitur astris” reveals where on the spectrum they lay and how they applied astrology to reach that conclusion.

To explore these issues in this paper, I adopt two outwardly contradictory methodologies, which hopefully—like my historical subjects’ positions on free will and determinism—complement one another. On the one hand, this paper is a broad, far-reaching, diachronic survey of astrological criticism and apologia across nearly four centuries of Western European cultural and intellectual history. Addressing all uses of this phrase, which number in the thousands if not tens of thousands in my time range, is well beyond the scope of a study this size. I do, however, examine dozens of instances from a wide array of both printed and manuscript documents ranging from the canonical to the arcane to narrate how notions of wisdom and free will changed dramatically within the context of astrology.2 On the other hand, this paper is an analytical microhistory, closely following the trail of a single, three-word Latin phrase across the pages of those texts to unravel its changing phraseological meanings, even as the multi-word lexical unit, with occasional minor modifications, remained the same. This is not a philologically-driven paper. Rather, it borrows the concept of a “phraseme” from historical linguistics to demonstrate how the semantic meanings of the phrase transformed while the words themselves did not (e.g., Álvarez de la Granja 2008; Granger and Meunier 2008). With “sapiens dominabitur astris” as the main historical actor, I argue that one can discern a great deal about much larger cultural, religious, political, and scientific disputes by critically examining how the use of this phrase changed across time and in different sociocultural contexts.

These debates often hinge on how both historical figures who used this phrase and contemporary historians and cultural anthropologists have defined astrology. Astrology was more than simply a science of prediction using the stars and comprised a vast body of beliefs, knowledge, and practices with the overarching theme of understanding the relationship between humanity and the rest of the cosmos through an interpretation of stellar, solar, lunar, and planetary movement (Campion 2009, pp. ix–xix). Historian of science Lynn Thorndike (Thorndike 1955, p. 273) called it a “universal natural law,” while Renaissance historian Eugenio Garin (Garin 1982, p. 93) referred to it as “a general conception of reality and history.” More recently, Robin Barnes (Barnes 2016, p. 5) has cautioned that it is a mistake to impose a “metahistorical logic” upon astrology, reduce it to an abstraction, or define it as if it had an “essential, superhistorical meaning.” Such broad characterizations suggest not necessarily that astrology was all things to all people, but rather that its practice as a predictive science was one of many possibilities within a far vaster system of meaning that changed significantly over time.

Among non-historians, these recent definitions of astrology appear simultaneously more capacious but also much more specific. Some who study the historical and cultural relationship between the cosmos and humanity have adopted the phrase “astral knowledge” to better describe a category of beliefs and practices much broader than the term “astrology” can capture (e.g., Brentjes and Schäfer 2020; Rutz 2016). The term astral knowledge encompasses what in the modern world we divide into astronomy, astrology, celestial divination, behavioral psychology, social and historical theory, cosmology, certain aspects of medicine, meteorology, and agronomy, and many other things in between. One reason I follow the phrase “sapiens dominabitur astris” through history is that in a Venn diagram of these separate categories, it is enclosed by all circles.3

Despite this broader focus, some critics of the recent historiography of astrology have lamented that despite doing justice to “explaining” astrology as a cultural phenomenon of both past and present along basically sound social scientific lines, far too many historical treatments of astrology have failed to “provincialize reason,” have taken “disinterestedness” too seriously, or have not taken belief seriously enough. As Patrick Curry has put it (Curry 2005), they lack the “reflexivity” to fully “respect and accommodate the lived experience of their historical subjects, astrologers and their clients, as real and true to exactly the same extent and with the same qualifications…as the historian writing about them.” Taking up Curry’s challenge of reflecting on and engaging with astrology as a “form of life [and] a way of being in the world” (ibid., p. 274), historians informed by cultural anthropology have turned their attention to the practices of astrologers themselves rather than their contexts (Burnett and Greenbaum 2015). In a word, they have attempted to write “insider” rather than “outsider” histories. My hope for this essay is to reunite these disparate but closely related ways of addressing Western astrology or astral knowledge as practiced, believed, rationally accepted or rejected, and lived by individuals from the late thirteenth through late seventeenth centuries.

Though I am cognizant of these critical reevaluations of the history of astrology and attempt to incorporate their insights when possible, this paper remains within the tradition of cultural and intellectual history with astral knowledge as my topic of analysis. Though not directly engaged with the minutiae of astrological praxis, this paper discusses the philosophical, theological, and scientific implications of that praxis as addressed by its most ardent defenders, vehement critics, and incisive cultural commentators. After giving a brief synopsis of the possible origins and historiography of the phrase “sapiens dominabitur astris,” I examine the theological context of its arrival in the 1270s. I then briefly describe the scholastic reconciliation of Aristotelian natural philosophy and Ptolemaic cosmology with Catholic theology as it affected astrology. This synthesis reached an apogee with the late thirteenth-century theological works of Thomas Aquinas—right at the time the phrase exploded in prominence—and framed morally and scientifically valid astrological practice in the fourteenth and fifteenth centuries. Finally, I demonstrate how this unity fractured throughout the sixteenth and seventeenth centuries. Civic humanism, new forms of scientific critique, and the Protestant Reformation all upended astrological theory and practice. As astrologers and their defenders adopted a growing number of frameworks to legitimize their practice, the “wise man” of the phrase became a chameleon who, in different contexts, was politically cunning, socially savvy, mathematically adept, or complete in his submission to God. To examine the use of the phrase “sapiens dominabitur astris” is to view these broader debates in microcosm.

2. Sapiens Dominabitur Astris: Origins and Historiography of the Phrase

What was the origin of the maxim “sapiens dominabitur astris”? Most scholastics and astrologers credited Ptolemy, though it appears in none of his works, and many named him in the typical medieval fashion of pseudepigraphically citing revered authorities to add intellectual heft to one’s writings.4 Theodore Otto Wedel (Wedel 1920, pp. 135–42) was perhaps the first historian to bring attention to the frequent appearance of this adage in his now classic work, The Medieval Attitude toward Astrology, in which he described its “long and curious history” of misattribution to Ptolemy. Though Wedel admirably detailed the evolution of the phrase’s use, especially in medieval literature, he shed little light on its ultimate origins. The problem lay dormant in the historical scholarship on astrology until G.W. Coopland reawakened it in his analysis of the mid-fourteenth-century astrological critic Nicole Oresme. Coopland called the phrase’s existence one of the “minor mysteries of history” and complicated the question of its origins by demonstrating that several medieval and early modern writers attributed it to authoritative ancient figures other than Ptolemy. Ludovico Moro credited Virgil; François Villon cited King Solomon; Christine de Pizan confused Ptolemy the ancient scholar with the Alexandrian general and Greco-Egyptian king Ptolemy I Soter; and several others simply quoted it without citation at all (Coopland 1952, p. 176).

While modern scholars are still debating the origins of the phrase, most agree that by the mid- to late thirteenth century, “sapiens dominabitur astris” had entered the lexicon of those contesting the merits of astrological practice (Wedel 1920, pp. 135–42; Coopland 1952, pp. 175–77; Tester 1987, pp. 176–83; Stewart 1975, pp. 55–62; Hackett 2000, p. 79). The phrase is likely a notion distilled from two aphorisms (verba) of the pseudo-Ptolemaic work, Kitāb al-Ṯamara, better known in the Latin West as the Centiloquium, and passages from the introduction to Kitāb al-mudkhal al-kabīr of ca. 848, better known in the Latin West as the Introductorium maius in astrologiam, by the Persian astrologer Abū Ma’shar Ja‘far ibn Muhammed al-Balkhī (Albumasar) (Lemay 1962, pp. 42–8; Hendrix 2020). Both were translated into Latin in the 1130s, making them available to most Western scholars for the first time (Tester 1987, p. 152).5 The fifth verbum of the Centiloquium proclaimed that “a skillful person acquainted with the nature of the stars is enabled to avert many of their effects and to prepare himself for those effects before they arrive,” while the eighth verbum stated that “a sagacious mind improves the operation of the heavens, as a skillful farmer, by cultivation, improves nature” (Pseudo-Ptolemy 1936, p. 153). In the relevant passage from the Introductorium maius, Abū Ma‘shar wrote that he must “mention the benefit to the wise masters of stars through foreknowledge of the power of the conditions of the stars in this world which is evident to them” (Albumasar Introductorium maius in astrologiam 1.6.21–22).

Pinpointing passages that reflect the essence of the later Latin phrase in these earlier Islamicate works, however, does not suffice to reveal its genesis. For one, the Latin phrase is not a verbatim translation of what is found in either work. Furthermore, the origin of the Centiloquium itself is also still under considerable debate. Richard Lemay (Lemay 1978) argued that it was composed by Abū Ja‘far Aḥmad ibn Yūsuf (known in the Latin West as Pseudo-Haly). More recently, Jean-Patrice Boudet (Boudet 2020) has noted that while most Latin editions of this work derived from Aḥmad ibn Yūsuf’s version of ca. 912–922, linguistic evidence suggests he was inspired by an even earlier unknown edition of Greek, Syriac, or Arabic origin.6 Scott Hendrix has argued that, paraphrase or not, “sapiens dominabitur astris” retains the overall spirit of the passages from Abū Ma’shar, while its first unequivocal appearance is to be found in the corpus of Albertus Magnus, the earliest of which is in his De fato of 1256 (Hendrix 2020). In either case, the Centiloquium, a short book of one hundred pithy sayings, provided later medieval astrologers with a simplified, non-mathematical summary of the basic tenets of Western astrology, while the Introductorium maius became a key source on Aristotelian cosmological and Ptolemaic astrological systems (Boudet 2020; Boudet 2014; Boudet 2013; Lemay 1980, p. 127; Lemay 1978, pp. 91–107). Both served as sources for the ideas later encapsulated by the Latin phrase “sapiens dominabitur astris.”

Why deploy the phrase in astrological debate? Thirteenth-century astrologers and their apologists had ample reason for concern. At the behest of Pope John XXI, on 7 March 1277, the Bishop of Paris, Étienne Tempier, published a list of 219 condemnations at the University of Paris addressing the anxieties of theologians alarmed at Aristotelian natural philosophy’s encroachment upon Catholic doctrine (Thijssen 1997, p. 91). This was the culmination of over half a century of theological wrangling over the status of Aristotle, whose physics and metaphysics had been banned at the university altogether at the Council of Sens in 1210, “corrected” by William of Auxerre under direction from Pope Gregory IX in 1231, and excised of the accretions of the Muslim scholar Averroes in 1270 (Grant 1996, pp. 70–71). Aristotelian physics and Ptolemaic cosmology convincingly explained natural phenomena to later medieval natural philosophers, but they often appeared to contradict scripture. Aristotelian positions included an eternal cosmos, the inextricable connection between body and soul, the natural causation of all events, and the epistemological primacy of reason. These contradicted God’s creation of the world, the mortality of the body and immortality of the soul, the possibility of miracles or God’s direct intercession on earth, and the preeminence of faith (Grant 1979, p. 212). To reconcile these discrepancies, medieval scholars developed a sophisticated logical system to argue that these positions were not contradictions at all. To conservative theologians, some of these attempts went too far. While legally limited and likely ineffective in private, these prohibitions slowed the public scholastic synthesis of Aristotle and scripture. Because Ptolemaic astrology and cosmology relied heavily on Aristotelian natural philosophy, Bishop Tempier’s condemnations amounted to an attack on the worldview that made late medieval astrology possible.

These condemnations shaped the terms on which astrologers and their allies negotiated the problem of free will and determinism. Many scholars who defended astrology—including contemporaries of the condemnations, such as Albertus Magnus, Thomas Aquinas, and Roger Bacon—increasingly relied on the adage “sapiens dominabitur astris,” and others like it, as a response to the Church’s theological problems with astrology. Condemnations number 161 and 162 prohibited the belief that “the effects of the stars on free will are hidden” and that “our will is subject to the power of the heavenly bodies,” respectively (Tempier 1974, pp. 45–50).7 Tempier proclaimed that the official Church position should be that there were no hidden effects on the will, over which no stellar influence existed. The argument that astrology’s defenders applied drew strength from Ptolemy’s authority, and in quoting “sapiens dominabitur astris,” they affirmed that astrological practice did not, in fact, interfere with these theological standpoints.

Even before the condemnations, scholastics like the Franciscan natural philosopher Roger Bacon (Bacon [1267] 1961, pp. 270–71) had attempted to chart a middle course between the proclaimed certitude of the most daring astrologers and the blanket condemnations of conservative theologians. He hoped to temper the former’s zeal and the latter’s skepticism (Hackett 2000, p. 78). A scant few Western European supporters of astrology cited the phrase or its variants prior to 1277: Albertus in De fato (1256) and Summa theologiae (ca. 1268–74); Bacon, somewhat elliptically, in his Opus Majus (1267); and Berthold von Regensburg in a letter from ca. 1270 (Zambelli 1992, p. 71; Bacon [1267] 1961, pp. 270–71, 406; von Regensburg 1862, p. 50).8 Its explosion after the condemnations of 1277 strongly suggests that this pivotal event put astrologers on the defensive, at least among elites also engaged in theological debate (Grant 1982, pp. 537–39; Tester 1987, p. 177). Astrology’s most enthusiastic proponents used both the relevant verba from pseudo-Ptolemy’s Centiloquium and the phrase as they argued for the compatibility of free will and astrological prediction in the face of hostile theological authorities.

3. Scholastic Wise Men: The Thomistic Synthesis and the Orthodox Christian

For astrology’s defenders, the conventional scholastic position on astrological effects differentiated between the physical and psychological influence of the stars and adopted a dualistic position concerning body and soul. In the West, this position dated back to at least Augustine of Hippo, who had written in the early fifth century that stellar movement was clearly connected to natural changes such as the seasons and the tides (Augustine of Hippo De civitate dei 5.6). Consequently, the body, being corporeal, was directly subject to the effects of the stars, while the rational soul, being incorporeal, remained unaffected and always retained the ability to fully resist any stellar influence. Therefore, stellar influence could affect bodily illness, disturb the inner workings of the organs, or could incline people to be susceptible to certain bodily pleasures, like food, drink, or sex. The rational soul, however, remained unmoved by the stars and could always freely overcome these passions or direct the intellect in ways that combatted bodily maladies or personal dispositions. “Sapiens dominabitur astris” became shorthand for describing the wisdom inherent in recognizing the difference between what the stars influenced and what the will controlled, as well as the astrological knowledge necessary to disentangle the two.

Albertus Magnus—Dominican friar, doctor universalis, and accomplished natural philosopher—was especially fond of “sapiens dominabitur astris.”9 In what may be its first, verbatim appearance in Latin, he used it in his De fato (69/65–9) and Summa theologiae (Proem, 1.17.68.1, 381a), as well as a modified version of it in his De natura locorum (277b).10 He also used similar versions of the phrase in nearly every other work that touched on free will (liberum arbitrium), Aristotelian natural philosophy, or Catholic theology, including De mineralibus, De quindecim problematibus, and Super ethica (Price 1980, pp. 181–82 and 184; Rinotas 2015, pp. 177–80). A version of the phrase is also found in the deliberately anonymous Speculum Astronomiae of ca. 1260 (Albertus [1260] 1992, 13.54–9, pp. 260–61). This theoretical treatise that separated the licit from the illicit aspects of astrology had long been unproblematically attributed to Albertus. However, recent scholarship has cast some doubt over his authorship of this text.11 Its most notable English translators Charles Burnett, Kristen Lippencott, David Pingree, and Paola Zambelli credited Albertus in their work (Zambelli 1992, pp. xi–xii, xiv, 3–5, 30, 124). More recently, Jeremiah Hackett (Hackett 2013, p. 448–49) claims to have ruled out Albertus as the author on paleographical and codicological grounds, while H. Darrell Rutkin (Rutkin 2013, pp. 483–90, 501–3) has averred that textual comparisons between the Speculum Astronomiae and earlier verified works strongly suggests that Albertus, after a major evolution in thought about astrology, may in fact have been the author. Regarding the phrase “sapiens dominabitur astris,” as noted above, Scott Hendrix has argued that although Abū Ma’shar appears to have been the first to use language embodying the ethos of the phrase in Arabic, Albertus is responsible for its first appearance in Latin, and he suggests that because Albertus misattributed the phrase to Ptolemy, this became the standard citation by those who followed his (and later Thomas Aquinas’s) interpretation.

In any case, whoever wrote the Speculum Astronomiae directly quoted both the fifth and eighth verba of pseudo-Ptolemy’s Centiloquium to argue that astrology provided the tools for thwarting an unfavorable forecast, explaining that an “impediment that is foreseen could be removed, totally or in part, and yet the operation of heaven is not frustrated but perfected” (Albertus [1260] 1992, 13.36–8, pp. 258–59).12 Medicine provides an excellent example. In late medieval astrological medicine, physicians associated certain planets and zodiac signs with certain humors, parts of the body, ailments, herbs, and drugs. When surgeons made an incision in a patient’s body for bloodletting, they had to account for which constellation the moon was in or risk the patient’s bleeding to death (Sirasi 1990; Campion 2009, pp. 76–77, 80–81). The author of the Speculum Astronomiae recounted tales of “miserable surgeons” (misero chirurgicos) and those “ignorant in medicine and astrology” who killed their patients by “bleeding from the arm while the Moon was in Gemini” and attempting to remove a stomach ulcer “whilst the Moon was in Scorpio” (Albertus [1260] 1992, 15.17–48, pp. 268–69).13 Ignorance of the stars’ positions could lead to tragic results, while knowledge of them provided one with the ability to avoid those consequences.

Albertus combatted the perceived determinism of astrological prediction and promoted those that emphasized choice. For Albertus, astrology existed not as a blueprint for a specific future but as a method of assessing the probability of events because if astrologers predicted things that “happen[ed] by necessity,” there would be no point in studying them at all, for we would be resigned to our fate anyway (Zambelli 1992, pp. 70–71, 167 n.43 and 44).14 Albertus derived this position on free will not from Augustine but from Ptolemy (Ptolemy 1936, 1.3 and 3.13, pp. 11–12, 89–91), who had argued in the Tetrabiblos that astrological prediction only made sense in the first place if the results were changeable. By understanding the movement of the stars, astrologers could delay or alter unfavorable predictions (Campion 2009, p. 45). As Albertus wrote, “those qualities [of the material world], because of contrary natural properties and different dispositions, often exclude the effects of heavenly motions. For this reason, Ptolemy says that ‘the wise man will be master of the stars’” (Albertus Magnus De fato 69/65–69).15 Essentially, Albertus found astrological prediction highly fallible but extremely useful and argued that the interposition of matter between the stars and people made potential futures legible to the astrologer. Consequently, he supported astrological medicine, the use of astrology for weather prediction and agriculture, electional astrology (where the practitioner decides on the astrologically appropriate time for an event), horary astrology (where the practitioner casts a horoscope when a particular question is asked), and natal astrology (one’s traits based on the position of the stars at one’s birth) as long as they pertained to the physical body and not the soul (Price 1980, p. 181; Campion 2009, pp. 45–51). These positions on astrology’s subdivisions became the dominant interpretation among astrologers in Western Christendom.

If Albertus provided the tools for reconciling astrological prediction with orthodox Catholic notions of free will, then his greatest student Thomas Aquinas used them to build an astrological framework acceptable to the Church. Aquinas attempted to resolve the perceived discrepancies between Aristotelian philosophy and Christian doctrine, and through what became known as the Thomist synthesis, Aquinas contributed directly to the debate over free will, determinism, and astrological prediction (Litt 1963, esp. pp. 206–19; Rutkin 2019, pp. 208–14). Expanding upon the work of Albertus, Aquinas employed “sapiens dominabitur astris” in his Summa contra gentiles and his seminal work, the Summa theologica, to assert that the “wise man” was one educated in the astrological practice necessary to choose auspicious moments and avoid inauspicious ones, a reasoned intellect who could control his passions, and a pious Christian capable exercising such judgment (Tester 1987, p. 181). In Summa theologica, Aquinas ([1266–1273] 1948, 1.1.115.4, p. 564) asked “whether the heavenly bodies are the cause of human acts,” to which he answered:

The majority of men follow their passions, which are movements of the sensitive appetite, in which movements of the heavenly bodies can cooperate: but few are wise enough to resist these passions. Consequently, astrologers are able to foretell the truth in the majority of cases, especially in a general way. But not in particular cases; for nothing prevents man resisting his passions by his free-will. Wherefore the astrologers themselves are wont to say that ‘the wise man is master of the stars’, forasmuch as, to wit, he conquers his passions.

The wise man was one in control of his baser instincts. Here, free will was important not just as a necessity so humans could freely choose to follow Christ but also to preserve sin as a choice between good and evil, as it did not have the “quality of a moral evil” unless it was entered into “voluntarily” (Aquinas [1266–1273] 1948, 2.74.1–2.75.1, pp. 919–20 and 927–28).16

Like Albertus, Aquinas conceded that terrestrial material was subject to the movement of the heavens, and even suggested that the intellect, being connected as it was to the physical mind, could be affected by the stars. However, for Aquinas ([1259–1265] 1928, 3.84, pp. 1–5), this was only an “indirect” or “accidental” effect (indirecte et per accidens).17 Aquinas argued that if “the heavenly bodies can directly and of themselves act on bodies…it would follow of necessity that the heavenly bodies are the cause of human choice and action” (Aquinas [1266–1273] 1948, 1.1.115.4, p. 564). Aquinas rejected this “determinate action” as “manifestly false…and contrary to human habit” because the intellect and will were separate and the stars affected them differently. Like the body, the intellect, an aspect of the physical mind, was susceptible to stellar influence, but the immaterial will retained “the power of following the passions or repressing them” (ibid.). Therefore, he argued, “the impressions of the heavenly bodies, by virtue of which the inferior powers can be changed, has less influence on the will, which is the proximate cause of human actions, than on the intellect” (ibid.). Aquinas attributed the greatest success of astrological prediction to the fact that most people simply did follow their passions—that is, made decisions based on their senses—rather than exercising rational judgment. More to the point, the intellect, being housed in the mind, could rationally convince itself that it was exercising judgment when in fact it was blindly adhering to the stellar portents. It took an active, immaterial will to steer the intellect in the right direction. Aquinas claimed that the ability to use one’s intellect to tame one’s passions meant that all people had the capacity to exert free will no matter what the stars signified, even if most did not. According to Aquinas, astrological knowledge gave one the power to know how the stars affected one’s body and mind, including how one might be inclined toward a particular sin, thus giving him the power to avoid it. In this, Aquinas developed another adage that also saw recurring usage, often in conjunction with “sapiens dominabitur astris”: “astra non compellunt, sed inclinant” (the stars do not compel, but they do incline) (Boruchoff 2009, p. 384).18 These positions developed by Albertus and Aquinas and elaborated upon and codified by later medieval scholastics characterized a sort of “truce” between astrological prediction and orthodox, Catholic Christian positions on the soul, will, intellect, and bodily passions that lasted for over two centuries.

4. The Reign of the Thomist Interpretation, ca. 1280–1500

After Aquinas’s work in the 1270s, the phrase “sapiens dominabitur astris” became a convenient marker of the shifting opinions on how orthodox Christians should practice astrology. While some wrestled philosophically with the implications of the possible contradictions between definitive astrological prediction and Christian free will, others simply quoted it as a facile demonstration of their commitment to this orthodoxy, before adhering to a more-or-less uncritical understanding of astrological prediction (Coopland 1952, p. 176). From the early fourteenth through the mid-fifteenth centuries, there was a veritable cornucopia of this form of orthodoxy virtue signaling. Some, including practicing astrologers John of Saxony (Saxony 1485) and Cecco d’Ascoli (d’Ascoli [1327] 1820, p. 6) employed the maxim to promote the practical advantages of astronomical study, while others, like Arnaldus de Villa Nova quoted it to remind his readers of the vital connection between astrology and medicine (Wedel 1920, pp. 136–37 n.4; Tester 1987, p. 186). Giovanni da Legnano (da Legnano [1390] 1917, p. 82) quoted it three times in his allegorical astrologico-political treatise on war De Bello, suggesting that possessing astrological knowledge was akin to preparation for combat (Coopland 1952, p. 176). James Yonge’s Middle English translation of the Secretum secretorum, a pseudo-Aristotelian compilation of esoterica, included an oblique reference to it as an adage “at the begynnyng of the Centiloge of Tholomewe,” rendered as “every wyse man have vertu and will,” where “vertu” meant stellar influence on character (Steele 1898, p. 216; Wedel 1920, p. 137). In one of the more notable, if little noted, references, the phrase appears in the first section of the infamous witch-hunting manual the Malleus Maleficarum (1484) of Heinrich Kramer and Jacob Sprenger (Kramer and Sprenger [1484] 1928, p. 33), in which they asked whether “the influence of the stars is in some way conducive to the wickedness of witches.” Its use here was evidently designed both to place the blame for witchcraft squarely on the perpetrators of these acts and to absolve the stars of any direct influence over the motives and exploits of accused witches. Kramer and Sprenger (ibid.) hewed closely to the Thomistic interpretation, arguing that the “disposition [of the stars] must not be said to be necessary, immediate, and sufficient, but distant and contingent,” and suggesting, like Aquinas, that anyone could resist the influence of the stars but that most chose not to.

By the fourteenth century, use of “sapiens dominabitur astris” and its variants had also seeped into medieval literature, in both Latin and vernacular languages, suggesting that it had developed a broader cultural significance beyond narrow astrological and theological disputes. All basically followed the Thomistic synthesis. While many writers employed astrological terminology and imagery rhetorically, as plot devices, or as ways to explain the motivations of characters, creative license permitted them to expound upon the free will debate within astrology in relatively innocuous ways. Already in 1275, Jean de Meun’s allegorical Middle French poem the Roman de la Rose contained lengthy passages on the relationship between the fates of individuals and the influence of the stars upon them. Like Aquinas’s wise man, de Meun’s had tamed his passions, after which knowledge of the stars could only be beneficial, “for he that could foreknow the things that heaven wished to do could surely prevent them” (de Lorris and de Meun [1230–1275] 1971, lines 17, 502–726, pp. 292–95).19 Dante Alighieri (Dante [1308–1320] 1961b, 16.67–83, pp. 212–13) captured the spirit of the phrase in the sixteenth canto of Purgatorio, where Marco Lombardo upheld free will and lambasted astrological determinism, claiming that “the heavens initiate your impulses,” but since God created all people with agency, “the mind in you…the heavens have not their charge.” Curiously, in his Acerba, the astrologer d’Ascoli ([1327] 1820, pp. 719–36) had accused Dante of not denying astrological determinism strongly enough, though he referred to the seventh canto of the Inferno, in which Dante (Dante [1308–1320] 1961a, 7.89, pp. 102–3) wrote that “necessity makes her [fortune] swift” (necessità la fa esser veloce), and otherwise ignored Dante’s preservation of free will in precisely the way astrologers regularly did through the phrase. The late fourteenth-century Bolognese lecturer Benvenuto da Imola later defended what he believed to be Dante’s orthodox positions on free will in his 1380 commentary on the Divina Commedia, the Commentum, by quoting the sixteenth canto of Purgatorio in conjunction with the phrase (Wedel 1920, p. 137 n.3; Barolini 2014).20

The English poet John Gower added an even deeper moral dimension to its meaning, expanding on both Aquinas and de Meun. In his poem Vox Clamantis, which recounted the failed English peasant’s revolt of 1381, Gower defined the “wise man” not only as a pious Christian but as one who had acquiesced completely to the power of God: the “vir sapiens” was now the “vir mediante Deo sapiens,” and that wisdom arose specifically through the “intermediary” of God Himself (Wedel 1920, pp. 135, 140–41). Gower’s “wise man” liberated himself from the influence of the heavens through devotion to God and the faith that His influence was stronger than that of the stars. This addition of modifiers into the original phrase helped to narrow the meaning of “wise” in its various uses and became more common as the original phrase became more well-known. Arnaldus de Villa Nova rendered the phrases as “vir sapiens dominabitur astris sua rationabilitate,” emphasizing the “reasonableness” of the wise man and defining reason specifically as one who followed the teachings of Hippocrates in medicine (Tester 1987, p. 186). In his Concordantia astronomie cum hystorica narratione, the Catholic cardinal and practicing astrologer Pierre d’Ailly (d’Ailly 1490, fol. d7v) contorted the phrase into “sed deus est ille vere sapiens qui solus dominabitur astris” (but God is the true sage who alone rules the stars). This both preserved its original connotations while at the same time reminding the reader that even if the stars inclined people in certain ways, God ultimately controlled the stars (Ackerman Smoller 1994, pp. 30, 63–64, 105, 193 n.13, and 205 n.18). By placing God atop the hierarchy of influence, d’Ailly suggested that any effect of the stars ultimately derived from God and therefore the proper practice of astrology was perfectly appropriate for Christians.

Even as astrology’s defenders complicated the relationship between the influence of the stars and human free will, others read “sapiens dominabitur astris,” as an indictment of astrological practices at odds with nascent conceptions of applied mathematics, consilience between the sciences, and the rational evaluation of evidence. Nicole Oresme, an especially vociferous opponent of astrology, used the phrase as an example of astrologers’ illogical rationales to justify their practice. In his 1350 anti-divinatory tract Livre de Divinacions, Oresme acknowledged, like Albertus, Aquinas, and most late medieval astrologers, that certain “weak and distant” effects of the stars might be pertinent for “sailors or farmers” (Oresme [1350] 1952, pp. 67–69).21 However, Oresme openly mocked the idea that astrologers were simply exercising their free will by learning astrological practice. Oresme was an accomplished mathematician and heaped scorn upon astrology as a field of study unworthy of higher mathematics. He claimed that a lack of mathematical and observational accuracy was precisely what made astrology an illegitimate discipline in the first place, since “the rules of astrology are based on poetry and rhetoric” rather than on precise mathematics; thus, “their predictions…were variable and discordant” (Oresme [1350] 1952, p. 87; Cadden 1997, p. 228). It was the misuse of calculation, not the exercise of free will, that rendered astrological prediction subject to error. Since “the disposition of the heavens cannot be completely known” according to Oresme ([1350] 1952, p. 87), then these “fables and imaginings … cannot be accepted as a natural science.” By setting up pseudo-Ptolemy’s proposition of “mastering the stars” as a logically incoherent fallacy based on a misapplication of mathematics, Oresme argued that no degree of wisdom could possibly give humans the ability to understand the stars in any meaningful way (Caroti 1987b).

Other critics of astrology noted its pagan origins, its incompatibility with various sciences, or the fact that the simple use of the phrase did not absolve one of the contents of the rest of the text. Again, what essentially all of these uses of the phrase from the late thirteenth through late fifteenth centuries had in common—whether used in pro- or anti-astrological writings—is that all exhibited some debt to the Thomistic interpretation of the relationship between Christian free will and power of the stars to incline. For instance, in a letter to his regular correspondent Giovanni Boccaccio, the Italian poet Francesco Petrarch (Petrarch 1581, p. 770) dismissed the phrase as “poor praise,” which “healthy ears rejected.” The theologian Bernardino da Siena wrote that the phrase was suspect as “a saying of the pagans,” and that even if it was true, it actually suggested that stars had no power whatsoever. Even as he criticized astrology, Bernardino proposed that knowledge attained from studying the movement of the heavens for medicine was good solely to “take away the force from the planet which is passing at that time” (da Siena 1880, p. 38; Garin 1982, pp. 32–33). In a letter to the Augustinian canon Wilhelmus Hermannus using arguments similar to those found in Giovanni Pico della Mirandola’s recently published screed against judicial astrology, the Disputationes adversus astrologiam divinatricem (1496), the French philosopher Robert Gaguin cited it as an expression used by astrologers to obscure their heterodox religious beliefs (Gaguin 1904, pp. 27–28; Zambelli 2007, pp. 49–50; Vanden Broecke 2003, esp. pp. 55–80). As Sylwia Konarska-Zimnicka has recently demonstrated, the phrase, in part, formed the centerpiece of the official debates over astrology at the University of Krakow in the mid- to late fifteenth century, with most professors claiming that adherence to the phrase’s ethos did not, in fact, properly insulate scholars from charges of determinism (Konarska-Zimnicka 2017, pp. 93, 97; Konarska-Zimnicka 2011).22 Two cultural shifts splintered the Thomistic philosophical cohesion around the turn of the sixteenth century: the rise of humanist interpretations of the role of fortune in social and political affairs and the radical shift in the free will/determinism debate in the wake of the Protestant Reformation.

5. Early Modern Fracturing 1: Humanist Political Reinterpretations

The Thomistic synthesis of Aristotelianism and Catholic theology, which had undergirded Western intellectual culture and scholarship for nearly a quarter of a millennium, began to disintegrate in the early sixteenth century. This upheaval left the relationship between astrology and free will in a state of flux. The rediscovery of the philosophies of classical antiquity and the new cultural emphasis on civic engagement provided a new sociopolitical context for the “wise man” and how he might exert power, while the Protestant Reformation, and especially Calvinist views on predestination, upended the longstanding Thomistic understanding of free will (Willis and Curry 2004, p. 1; van Asselt et al. 2010; Penny 1990; Vanden Broecke 2003; Garin 1982; Barnes 2016, esp. pp. 7–10, 69, 163–66, 215–58).23 Because of its ubiquity in sixteenth- and seventeenth-century culture, astrology, and particularly the use of the phrase “sapiens dominabitur astris,” provides an important lens through which to view these broader social and cultural debates.

For astrology, the authority of the Thomistic synthesis had lain in its fusing the rational intellect with the pious, orthodox Christian. The truly wise man must be both. While this interpretation did not lapse completely beginning in the sixteenth century, the wise man of humanist political culture also developed new connotations of shrewdness, political savvy, and the ability to navigate the capriciousness of social fortune. The best example comes from the writings of Niccolò Machiavelli. In several of his works, he defined the “wise man” in ethical terms as an astute participant in the political sphere. In general, Machiavelli, like the scholastics before him, saw humans as inclined but not compelled by the stars (or nature in general) to behave in certain ways. This was the precise position he took in a probably unsent letter of 1506, addressed to Giovan Battista Soderini, son of the Florentine statesman under whom Machiavelli served as chancellor and ambassador. Using language reflecting the essence of the phrase “sapiens dominabitur astris,” Machiavelli wrote that any man “wise enough to understand both the times and the pattern of events, and to adapt himself to them, would always have good fortune or would always protect himself from bad fortune, and it would become true that the wise man would command the stars and the Fates” (Machiavelli 2019, p. 33). This position differed little from the Thomistic uses of the previous two and a half centuries. Indeed, Machiavelli used a variant of the phrase in this way at least three times: in letters to his personal astrologer Bartolomeo Vespucci in 1504, in the Soderini letter of 1506, and in Chapter 25 of The Prince (Parel 1991).

Where Machiavelli broke from the earlier scholastic position was his apparent belief that there was no such thing as a “wise man” capable of fully mastering the stars, which implied more command over fate than humans possessed. Far from succumbing to a strict determinist view of human nature, Machiavelli remained equally doubtful of the capacity of the stars to exert much specific influence over humanity at all. Historian of political thought Anthony J. Parel (Parel 1993, p. 80; Parel 1992) has argued that Ptolemy’s astrological works served as a source for Machiavelli’s interpretation of “fortune” and his quotations of “sapiens dominabitur astris” and Ptolemy’s works on astrology certainly corroborate this. Referring generally to fortune, as opposed specifically to astrological influence, Machiavelli wrote in The Prince that

it is not unknown to me how many men have had, and still have, the opinion that the affairs of the world are in such wise governed by fortune and by God that men with their wisdom cannot direct them and that no one can even help them; and because of this they would have us believe that it is not necessary to labour much in affairs, but to let chance govern them. This opinion has been more credited in our times because of the great changes in affairs which have been seen, and may still be seen, every day, beyond all human conjecture. Sometimes pondering over this, I am in some degree inclined to their opinion. Nevertheless, not to extinguish our free will, I hold it to be true that Fortune is the arbiter of one-half of our actions, but that she still leaves us to direct the other half, or perhaps a little less.

(Machiavelli [1532] 2005, p. 84.)

Machiavelli simply struck for middle ground between the role of fortune and free will in human affairs. He argued that acting in accordance with nature depended less on astrological influence and more on the “times and the temperament” (ibid.). Unlike the Thomist interpretation, the Machiavellian combined a rejection of both astrological determinism and Christian free will—at least as defined by the scholastics—as well as an acknowledgment that humanity was inclined by the natural forces of “temperament and humor” (ibid.). Even though he changed the influencing factors, he maintained a soft determinism by refusing to consider any man wise enough to be in full control of his destiny. Most men, he claimed, were not wise but “shortsighted” and could not “command the nature” of the stars or fate. Rather, he argued, “fortune varies and commands men and holds them under her yoke” (Machiavelli 2019, p. 33). According to Ernst Cassirer, Machiavelli defined a wise man as someone more than learned or even politically perceptive, and instead as someone who possessed both the power and the will to apply his limited wisdom for his own personal gain. In what Cassirer called the “secularization of the symbol of Fortune,” Machiavelli aptly compared the astrologers’ power to use their knowledge to determine potential fortunes with the will of intellectually and socially powerful men to change their political destinies (Cassirer 1947, p. 160; Cassirer 1963, esp. pp. 64–66, 84–91, 109–12).

The political spirit of the “wise man” became especially important throughout the sixteenth century. Those quoting “sapiens dominabitur astris” no longer simply used it to resolve discrepancies between free will and divine providence. They also wielded it to discuss the role of personal political action versus quiet meditative prayer, the proper role of reason in civic affairs, and the degree to which fortune, chance, and human deeds determined the outcome of events on both cosmic and individual scales (van Heijnsbergen 2004, p. 208; Stewart 1975, pp. 57–59). For example, in his 1549 Complaynt of Scotland, a propaganda pamphlet of ballads and allegories emphasizing Scotland’s distinctiveness compared to England, Robert Wedderburn deployed the phrase as the key to interpreting the rest of the work’s politics. For him, it signified the choice between accepting a political arrangement beyond one’s control and challenging it. Unlike the careful middle ground between chance and human action forged by Machiavelli, Wedderburn loathed the defeatist indifference that some Scots exhibited toward English incursions into Scotland during the Rough Wooing, an English attempt to break a Franco-Scottish alliance and force a marriage between Mary, Queen of Scots, and the young English king Edward VI (Merriman 2000). Wedderburn urged people to take matters into their own hands in order to “master the stars,” so to speak. To him, determinism equated to political apathy, while free will meant united Scottish resistance to English invasion (Stewart 1975; Ridder-Patrick 2012).

6. Early Modern Fracturing 2: The Protestant “Fleshly Man” and Everyday Astrology

Beyond civic humanist reinterpretations, the Protestant Reformation, beginning with Luther in 1517, created new theological space for a radical reimagining of how wise men related to free will within an astrological context. Some Protestant views of free will underscore a similar shift in both the definition of the wise man and proper astrological practice. The official Catholic position, as we have seen, upheld the idea of free will, while noting that it did not exist apart from or outside of divine grace. Catholic scholars elaborated on this position as early as Augustine, and in the wake of the Reformation, Church officials reinforced it in even stronger language at the Council of Trent (Waterworth 1835, 6.1 and 6.5, pp. 33–35). While Calvinists adopted the most extreme position against free will, arguing that all people were predestined from birth either for heaven or hell, even they, along with Lutherans, maintained that in everyday affairs people acted voluntarily and without compulsion. Exercising what theologian Richard A. Muller has called “synchronic contingency,” Reformed thinkers posited that people maintained the power of free, contrary choice at any given instant (Muller 2020). Put another way, divine foreknowledge did not imply continuous divine control, except under special circumstances where God intervened directly in human affairs. However, these free actions applied solely to temporal matters. For Calvinists, souls remained in bondage to sin. For Lutherans, souls were beholden to God or Satan. For Arminians, the other major Protestant philosophy on predestination, no one was compelled by necessity, but there was no freedom from sin apart from “prevenient grace,” in which divine grace preceded individual decision-making (Calvin [1536] 1845, 2.3.5, 3.3.6, and 3.23.2; Luther [1525] 1823, p. 66; Stanglin and McCall 2012). What all had in common was that freedom of the will did not apply to salvation, which was based on faith alone (sola fide).

Thus, in the Protestant context, astrologers debated the wise man, mastery of the stars, and the legitimate practice of astrology entirely in temporal, secular terms, with little concern for the cosmic implications of salvation or even the fates of individual souls. These were entirely up to God and an individual’s faith; astrology had no bearing on these questions. Instead of quelling astrology, this emphasis freed Protestant astrologers to focus on how the stars affected medicine, agriculture, weather, or other mundane matters over which individuals did possess control. Despite gaining license under these Protestant interpretations, this focus on everyday affairs profoundly tempered the expectations of what astrological prediction offered while simultaneously liberating it from serious religious criticism. For example, medicine—as seen in the examples of Albertus Magnus, Arnaldus de Villa Nova, and Bernardino da Siena—remained one of the most crucial allies of astrology, because physicians believed stellar position affected certain parts of the body. So-called “Zodiac man” images depicting this relationship became extraordinarily common at the dawn of the print era. One notable copper etching, created by the French engraver Pierre Miotte for Athanasius Kircher’s Ars magna lucis et umbrae (Kircher 1646), featured both the phrases “inclanant non necessitant” and “sapiens dominabitur astris” emblazoned across banners at the head and feet of a Zodiac man, while a complex grid denoting the correspondence between constellation, planet, and body part was superimposed over him (Figure 1).

Predictive astrology in the Protestant context regularly emphasized the abject helplessness of people against the mighty power of God, but as part of God’s handiwork, the stars revealed a divinely ordered nature within which people had agency. The Protestant emphasis on making “every man his own priest” resonated among the astrologically inclined, and the sixteenth century witnessed a sharp rise in astrological practice and publication among minor professors, preachers, physicians, midwives, pamphleteers, almanac-compilers, and other non-elite practitioners (Barnes 2016, p. 6). Astrologer-preachers, particularly in sixteenth-century Germany, but also in Protestant centers in the Low Countries and England, published practica, or short booklets with a year’s worth of astrological predictions, with few qualms about contravening free will.24 Like the Thomist man of passion, the Protestant “fleshly man” (fleischlich Mann), as German astrologers Bartholomew Mangolt and Johann Shöner put it, was subject to the stars (Barnes 2016, p. 6; Caroti 1987a).25 However, the Protestant will was quite different. True agency belonged only to God, “a free agent, [and not] some Stoic principle…watch[ing] over his handiwork, and exercis[ing] his wonderful rule especially over his elect,” as the pastor and astrologer Hieronymus Wilhelm described it (Barnes 2016, p. 164).26 The best people could do was submit to God’s will. For Protestant astrologers, who overall interpreted the stars as signs of God’s will, this meant that adapting one’s behaviors based on astrological prediction, in fact, meant fulfilling that will. As the Coburg town physician (stadtphysicus) and astrologer Christoph Stathmion put it, “man is established in and ordained by God in a way that without natural means and without natural knowledge of the Creation, he cannot and may not live long according to the divine order; thus [astrology]…is most highly necessary for the maintenance of his temporal life” (ibid., p. 166).27 Notably, again, it was his temporal and not eternal life.

Several uses of “sapiens dominabitur astris,” particularly in England, reflect these new Protestant positions on free will and how astrologers chose to navigate them (Boruchoff 2009, p. 386). Between the 1480s and the 1690s, we find the phrase in nearly one hundred printed books in the English language—not counting almanacs and other ephemera—with the preponderance coming between the 1620s and the 1690s.28 Many, perhaps most, quoted the phrase in defense of astrological practice in ways little different from previous uses in the fourteenth and fifteenth centuries, and it appeared in a wide variety of genres. In his astronomy textbook The Castle of Knowledge, Robert Recorde (Recorde 1556, p. 4) quoted it to defend both astrology and astronomy as the “moste necessary study … for any man that desireth perfection of wisedome” with benefits for the “true knowledge of husbandrie and navigation.” The Anglican bishop Henry King (King 1628, pp. 78–79) quoted it in an exposition of the meanings of the Lord’s Prayer to argue that “the miseries of our lives” were not the fault of the stars but were “rooted in our Natures, [for] there is no man throughly miserable, but hee that makes himselfe so, and no [prediction] fatall but unto him that beleeves it.” It appeared on a woodcut print in George Wither’s Collection of Emblems, Ancient and Moderne (Wither 1635) outlining a king with the “eye of Providence” standing atop a globe containing all of the zodiac signs, while in the background figures hold a cross toward the stars (Figure 2). Moreover, we find it in the best-selling general astrological work in seventeenth-century England, William Lilly’s Christian Astrology, in which he wrote that the entire purpose of drawing nativities was “to arm against affliction beforehand” (Lilly [1647] 2005, p. 819; Bamborough and Eade 1981).

Yet, the idiosyncrasy of some of the more prominent uses reflect its demise as a sturdy defense of astrological practice and its development as a cudgel that authors wielded to expound upon individual positions on will, wisdom, the effect of the stars, or the practice of astrology in general. Representative of this fracturing, for example, Anglican clergyman and Oxford lecturer John Chamber quoted it three times in his polemic A Treatise against Judicial Astrology. In one instance, echoing Oresme’s complaints, he called it a mere “oratoricall and poeticall proofe” rather than a “grounded demonstracion” and suggested that not even Ptolemy thought it sufficed to defend astrology (Chamber 1601, p. 65). In another, noting the tautology of stellar influence in a way reminiscent of Bernardino da Siena’s criticism, he wrote that “if our actions be in our owne election to make them better or worse, by chusing a fit or unfit day for them, how can the stars be said to rule and guide them? for if the stars rule them, they are not in our election, and if they be in our election, the stars do not rule them” (ibid., pp. 87–88). Statesman and natural philosopher Francis Bacon referred to it in his Advancement of Learning to suggest that “mastery” meant a “spur to industry” and that it was not a platitude for astrologers but rather an allegory for seizing technological and economic opportunity (Bacon [1605] 2000, p. 164; Cochrane 1958). In his famous diatribe against astrology, John Allen noted that even as a metaphor it was found wanting: “The Heathen could say Sapiens dominabitur Astris; A wise man will rule over the Stars,” and he listed other things like “grace, education, and civil wisdom” that gave people far more power over their destinies (Allen 1659, p. 4).

In some cases, it became denuded of its explicitly astrological meanings altogether. For example, it found its way into prominent seventeenth-century works such as Athanasius Kircher’s Mundus Subterraneus (Kircher 1665), a treatise on geology and geography featuring astrology only sparingly, where it appears on the frontispiece as a sort of shorthand surrogate for scientific knowledge through empirical observation (Figure 3). Like John Allen, Thomas Fitzherbert argued that the phrase was meant metaphorically and that “mastering the stars” need not have anything to do with the practice of astrology at all and was as simple as changing one’s diet, exposing oneself to “goode aire,” or acquiring an education (Fitzherbert 1606, p. 104). It appeared in Sir Walter Raleigh’s History of the World, Robert Burton’s Anatomy of Melancholy, the poetry of John Donne, and the plays of Thomas Tomkins. We even find it in the 1735 edition of Benjamin Franklin’s Poor Richard’s Almanack (Wedel 1920, pp. 137–138 n.3). Its appearance as a motto in his Almanack, though most likely satirical, reflected the combination of folksy proverbs, astrological lore, and astronomical data that characterized many mid eighteenth-century Anglo-American almanacs. By this point, however, astrology had fallen into irreparable disrepute among Enlightenment intelligentsia, had all but disappeared from European intellectual culture, and was well on its way to becoming a type of innocuous popular entertainment (Hunter 2020; Vermij and Hirai 2017; Kléber Monod 2013).29 While the debate between free will and determinism remained, of course, by the early eighteenth century, the rhetorical impact of astrology on such discussions in theological and philosophical spheres had largely subsided.

7. Conclusions

Even though its use waned precipitously at the end of the seventeenth century, along with astrology itself—at least in elite scientific circles—“sapiens dominabitur astris” has reappeared in various contexts since. Fräulein Anna Sprengel, a fictional creation of the theosophist and Freemason William Wynn Wescott, used it as a pseudonym when founding the occult secret society, the Golden Dawn, in the 1880s (McIntosh 2011). The Healy and Comer families in Scotland have used it in their family seals, and both Bergvliet High School in Cape Town, South Africa, and the Italian theater group Academia Intronanti have used it as their motto (van Heijnsbergen 2013, p. 79 n.51). Most recently, in 2016, the Ukrainian Defense Intelligence adopted it as its unofficial slogan, complete with a seal depicting an owl, that venerable symbol for wisdom, dangling a sword from its talons over Russian territory (Figure 4).30 Clearly, it still evokes power, freedom, and individual mastery whether one associates it with astrology or not.

“Sapiens dominabitur astris” and its many variations contained a multiplicity of meanings beginning in the late thirteenth century. The Parisian condemnations of 1277 created conditions in which it became more difficult to practice, or even support, astrology without first qualifying that acceptance with assurances that free will would be maintained. However, fearful apologia describes only the superficial importance of “sapiens dominabitur astris” because this phrase and its additional renderings also defined the proper boundaries of astrology and the “wise men” who practiced it.

If both free will and the practice of astrology were to coexist, later medieval astrologers and their defenders required new definitions for the “wise man” and new explanations of stellar mastery. For Aquinas and most scholastics who adhered to the Thomist synthesis, wisdom arose from the virtuous soul capable of transcending his baser nature, which was more susceptible to the influence of the stars, through the proper combination of reason and faith. In the sixteenth century, beginning with Machiavelli, the “wise man” became not only an intelligent or pious man but also a politically shrewd and socially perceptive individual capable of commanding his civic destiny within the admitted confines of larger cosmic forces. For Protestants, free will shrank in importance against the awesome power of God. Faith consumed all matters of salvation while the vast possibilities of astrology simultaneously expanded as a guide to mundane, secular matters. Astrologers, theologians, poets, natural philosophers, and other students of astral knowledge adopted the phrase to stake out a position on the relationships between fate and free will, fortune and agency, determinism and contingency, natural causes and divine intervention, the power of God and the power of the individual, and the influence of the stars and the astrologers’ capacity to understand it. These relationships were not dichotomous but dialectical, and it is precisely because they were not dichotomous that astrologers found such utility in the adage “sapiens dominabitur astris.”

Much work remains to be done for historians of astrology, early modern philosophy, and both Catholic and Protestant theology to better understand how to place astrological thought on these topics in the context of broader debates in the early modern world. Based on their tightrope walk over the safety net of “sapiens dominabitur astris,” a majority of astrologers and supporters of astrology might be defined as “compatibilists,” the philosophically libertarian position that individual free will is not mutually exclusive with a determinist account of cosmological causality. Yet, as scholars like Richard A. Muller have noted, attempting to pin down early modern views on fate, free will, and contingency in libertarian, compatibilist, or deterministic terms misunderstands these issues in a deeply anachronistic way (Muller 2020). Rather, their views depended greatly on how they understood causality, which underwent extraordinary changes as the Aristotelian and Ptolemaic cosmological system found itself in increasingly tough competition with other forms of natural philosophy. Early Renaissance philosophers adopted Stoic principles of humility in the face of uncertainty; Neoplatonism and atomism offered alternatives to causal certainty and universal design; and the mathematization of natural knowledge and public economic life provided new rationales for order (Akopyan 2021). That all of these changes bore heavy weight upon both astrology and the philosophies free will is no coincidence. As one of the primary bodies of astral knowledge, astrologers both adapted and resisted these transformations depending on context. The question was not so much one of free will versus fatalism nor any other binary. Rather, it was a question of how free will existed within a larger framework where some things were, in fact, predetermined and a question of how natural cause and effect existed in a cosmos where both people and God possessed agency.

For most European Christians of all religious denominations between the late thirteenth and late seventeenth centuries, astrology, when practiced appropriately, offered convincing answers to these questions. Yes, the axiom’s longevity attests to its convenience as a conscience-saving device and marker of theological orthodoxy. More importantly, it was an expedient indicator of how notions of valid astrological practice changed from the Later Middle Ages through the early modern era and how the theological, philosophical, and scientific context of that practice reflected those changes. Through this simple three-word Latin phrase, later medieval and early modern practitioners and believers in astral knowledge claimed the ability to preserve humanity’s free will and God’s supreme authority, define the wise man as astrologically knowledgeable, and delineate the proper boundaries of acceptable astrological practice.