**1. Introduction**

Our aim in this paper is to use a naturalistic approach to explore Jason Stanley's [1–4] notion of the *practical grasp* of a propositional truth, in light of his intellectualist approach in general. We show that there is more to his notion of "practical grasp" than merely a special kind of relation to a propositional truth, and that this added dimension raises questions about how reducible *knowledge how* is to *knowledge that*. In his investigation of knowledge, Stanley strives to position his theory as being compatible with cognitive science. We will show that his interpretations and conclusions are problematic.

There has arguably been an increased acceptance of naturalism among philosophers, in the sense of a wider acknowledgement of an "all-encompassing" natural world. There is consensus, too, on the importance of taking scientific evidence into account when dealing with philosophical problems, although there is much debate about what exactly such an acceptance ought to involve [5]. An *ontological* naturalism that excludes supernatural entities is nowadays largely uncontroversial. Physicalists [6] claim that physical entities and their arrangements underlie all causal interactions, but it is a much-debated question whether, for example, the mental can be reduced to the physical or not [7]. Influential positions in*methodological* naturalism include, for example, replacement naturalism [8], which claims that epistemology should be replaced with cognitive psychology; substantial naturalism [9], which holds that philosophical problems and issues need to be reformulated in a more strict scientific terminology in order to remain relevant; and cooperative naturalism [10], which claims that philosophy needs to take scientific findings into account where such findings exist. Furthermore, *evolutionary* naturalism [11,12] emphasizes that cognitive agents such as humans are shaped to fit their environment by natural selection. An evolution-based understanding of our cognitive structures and mechanisms can then be seen to replace, succeed, or complement traditional epistemological understandings [13].

We will take a physicalist-inspired approach within cooperative and complementary evolutionary naturalism that views all philosophical questions as being legitimate. The answers need to be

compatible with the natural world and the evolved cognitive agents in it, as well as with scientific results. If there is relevant scientific input concerning a particular question or problem at hand, it must be taken into account, and intuitions must give way. We consider this approach both inclusive and potentially fruitful, and so will use it to elucidate the aforementioned influential discussion concerning *knowledge*.

Section 2 briefly discusses Stanley's [1] explanation of how *knowledge how* differs from *knowledge that*. Sections 3–5 evaluate Stanley's basic argumen<sup>t</sup> in favour of intellectualism. Section 6 shows how his concept of *knowledge how* counts against elements of his intellectualist argument. Section 7 explores a possible objection to the alternative that we sketch, concluding that—even within Stanley's framework—There must be more to *knowledge how* than the grasp of a proposition. Section 8 presents insights from cognitive science to support our interpretation and discusses how Stanley's position is problematic.

## **2. The Argument from Knowledge Transfer**

A central element in Stanley's [1] theory of knowledge is that practical *knowledge how* can be reduced to propositional *knowledge that*. A general difficulty for any theory that attempts to reduce *knowledge how* to *knowledge that* is that of knowledge transfer. If *knowledge how* is essentially propositional, then it would seem that it ought to be easy to transfer propositionally; ye<sup>t</sup> it is not. Comprehending all the propositional truths about how to swim will not enable one to swim. One cannot learn it from a book. Success takes practice and time. One does not learn it, intellectually; one must learn to do it practically, in a way that seems to point towards some non-propositional proficiency.<sup>1</sup>

To accommodate this practical aspect of *knowledge how* whilst preserving his intellectualist account, Stanley defines *knowledge how* as the practical grasp of a propositional truth: to have mastered a skill is to have grasped a propositional truth in a "practical" way. For an agen<sup>t</sup> to act skillfully, according to Stanley, she must entertain "a practical way of thinking" [1] (pp. 124–130) concerning the true proposition(s) she knows (i.e., her knowledge how). She must grasp the way an action can be performed and be able to perform the action under relevant parameters of normality. She must apply the information she has acquired "in a first-person way" [1] (p. 124): that is, she must relate it to her practical capacities. In this way, *knowledge how* can be seen as propositional, despite possible appearances otherwise.

Given what it is meant to do, the practical grasp of a propositional truth must include the ability to apply that propositional truth practically. If learning to swim means gaining a practical grasp of the propositional truths about swimming, then that practical grasp includes being able to execute the necessary motions described by those propositions: i.e., acting on those propositions in *the right kind of way*. Stanley writes that the inspiration behind his idea can be found in Davidson's philosophy [15]. Davidson added the criterion "in the right way" to avoid the problem of deviant causal chains. Given his causal model, he needed a mechanism that prevents actions coming about in random ways. That said, exactly what constitutes the "right way" was unclear even to Davidson, who wrote [15] (p. 79): "I despair of spelling out ... the way in which attitudes must cause actions if they are to rationalize action." Many researchers have drawn attention to this: e.g., Stout [16] (p. 4) mentions "what Davidson famously despaired of spelling out." We think it just as difficult to account for "the right way" in Stanley's account. Stanley's notion of practical grasp has gone through many modifications over the years; we will not treat them all but will focus mostly on his formulation in [1]. Stanley and Williamson [3] write that the agen<sup>t</sup> must entertain a way of Φ-ing under a practical mode of presentation and that [3] (p. 429): "thinking of a way under a practical mode of presentation undoubtedly entails the possession of certain complex dispositions." Stanley [2], [1] builds on this idea

<sup>1</sup> For a thorough treatment of this problem, see Glick [14]. He calls it the *su*ffi*ciency problem*.

when he develops his view on "ways of thinking" [1] (ch. 4), which involves a "more sophisticated notion of [a] proposition" [1] (p. viii).

There are no uncontroversial views in the literature on the exact meaning of "proposition",<sup>2</sup> and Stanley's is especially hard to pin down. What is clear is that, on his view, propositions are facts and "a proposition is the sort of thing that is capable of being believed or asserted" [1] (p. vii). Thus, there is a duality to his conception: propositions are factual and, therefore, ontological; at the same time, they are something that one can stand in an epistemic relationship to. They appear among a subject's ways of thinking or in different *modes of presentation*.

This conception enables Stanley to argue that skilled action is propositional in character. It is propositional because the skilled agent, in acting, acts on a proposition that she grasps epistemically and can act on because she relates this knowledge to herself in a "first-person kind of way" (see [1] (pp. 85–86, 124–130)). The challenge for the intellectualist is that *S* can know a proposition *p* without knowing how to transfer *p* into action. One could know that *w* is a way to ride a bike without being able to ride a bike oneself: i.e., there is seemingly a difference between *knowledge that* and *knowledge how*. In his defense of intellectualism, Stanley suggests that *knowledge how* must comprise a special kind of grasp: the practical grasp of a proposition enabling the agen<sup>t</sup> to apply the truth she has acquired to her own agency ("a first person way of thinking" [1] (pp. 85–86)). *Knowledge how* does not consist of a propositional truth *per se* but rather the practical grasp of that propositional truth. The answer to a question about *knowledge how* does not consist of a proposition *per se* but of the "practical grasp" of that proposition, which is what constitutes the skill. When an agen<sup>t</sup> transforms her skill into practice, she does so under a "practical mode of presentation" [2]. The problem with this is that Stanley also argues [1] (pp. 126–128) that knowing how to do something need not mean being capable of doing it: i.e., *knowledge how* need not be the ability to execute a skilled action. Part of our critique is to ask: what *is* the practical presentation in question?
