Online research in philosophy

The primary aim of this essay is to explain the central elements of Locke's theory of knowledge. A secondary aim arises from the official definition of knowledge introduced in the opening lines of book IV. Though Locke's repeated statements of the definition are consistent with the initial formulation, the consensus view among commentators is that that official definition is in tension with other book IV doctrines. My broader interpretation involves an effort to render the various doctrines consistent with the official definition. The order of discussion: Section 1 explicates the definition of knowledge. Section 2 explains two main divisions of knowledge – namely, its three degrees, and the four sorts of knowable truths. In Section 3, I consider whether Locke understands knowable truths on a model of analyticity. Section 4 addresses potential problems about the objectivity of knowledge, given Locke's account. Section 5 focuses on external world knowledge – Locke calls this "sensitive knowledge" and it poses special difficulties for the official definition of knowledge.

Interpreters of Locke’s Essay are divided over whether to attribute to him a Representational Theory of Perception (RTP). Those who object to an RTP interpretation cite (among other things) Locke’s Book IV account of sensitive knowledge, contending that the account is incompatible with RTP. The aim of this paper is to rebut this kind of objection – to defend an RTP reading of the relevant Book IV passages. Specifically, I address four influential assumptions (about sensitive knowledge) cited by opponents of an RTP interpretation and argue that in each case the assumption is false.

Introduction -- Locke's theory of ideas -- Locke's theory of matter -- Locke's theory of language -- Locke's theory of identity -- Locke's theory of morality -- Locke's theory of knowledge.

Prologue -- Part 1: Property, personification, and idols: Owning things; the crying of lost things; making babies in the South Seas; the growth of idols; The rape of the lock as still life -- Part 2: Persons and fictions: Locke's wild fancies; fictionality and the representation of persons -- Part 3: Authors and nonpersons: me and my ink; things as authors; authors owning nothing.

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In the Essay Concerning Human Understanding, Locke insists that all knowledge consists in perception of the agreement or disagreement of ideas. However, he also insists that knowledge extends to outer reality, claiming that perception yields ‘sensitive knowledge’ of the existence of outer objects. Some scholars have argued that Locke did not really mean to restrict knowledge to perceptions of relations within the realm of ideas; others have argued that sensitive knowledge is not strictly speaking a form of knowledge for Locke. This chapter argues that Locke’s conception of sensitive knowledge is in fact compatible with his official definition of knowledge, and discusses his treatment of the problem of skepticism, both in the Essay and in the correspondence with Stillingfleet.

Saul Kripke has convinced many of us that material things have their material origins essentially. Plutarch, through his Ship of Theseus story, has convinced many of us that material things can sometimes survive gradual replacements of their material parts, that they are materially nonrigid. By way of a series of counterexamples, I will argue that any attempt to specify what in particular is essential about material origins will founder on the phenomenon of material non-rigidity.

I will defend a principle at work in Thomas Aquinas’s argument that the human intellect must be immaterial in order to know material things in SummaTheologica, Ia, q.75, a.2. Thomas relies on the position that whatever knows certain things would be impeded in this knowledge if it contained in itself thesesame things. Thus, if humans can, in principle, know all material things, then the intellect cannot be material. The position that a material intellect would be limited in knowledge of material things is perhaps the most controversial part of the argument. I will articulate a version of this argument and argue that two objections to Thomas’s argument, offered by Norman Kretzmann and Robert Pasnau, fail, due in large part to a misunderstanding of proper objects of cognition.