In this paper I argue that Locke takes sensitive knowledge (i.e. knowledge from sensation) to be genuine knowledge that material objects exist. Samuel Rickless has recently argued that, for Locke, sensitive knowledge is merely an “assurance”, or a highly probable judgment that falls short of certainty. In reply, I show that Locke sometimes uses “assurance” to describe certain knowledge, and so the use of the term “assurance” to describe sensitive knowledge does not entail that it is less than certain. Further, (...) I show that sensitive knowledge includes the perception of a relation between ideas, and thus it satisfies Locke’s definition of knowledge. He also repeatedly claims that sensitive knowledge is certain. So, despite recent challenges to this interpretation raised in the secondary literature, Locke really does take sensitive knowledge to be certain knowledge. (shrink)

Locke Defines Knowledge at the beginning of Book IV of the Essay concerning Human Understanding as “the perception of the connexion and agreement, or disagreement and repugnancy of any of our Ideas” (E IV.i.2).1 So defined, knowledge varies along two dimensions. On the one hand, there are four “sorts” of knowledge: of identity or diversity; relation; co-existence or necessary connection; and real existence. On the other hand, there are three “degrees” of knowledge: intuitive knowledge, which consists in the “immediate” perception (...) of agreement or disagreement between ideas (E IV.ii.1); demonstrative knowledge, which consists in the perception of agreement or disagreement by way of intermediate (or intervening) .. (shrink)

This book is a general introduction to the philosophy of John Locke, one of the most influential thinkers in modern times. Nicholas Jolley aims to show the fundamental unity of Locke's thought in his masterpiece, the Essay Concerning Human Understanding. In this work Locke advances a coherent theory of knowledge; as against Descartes he argues that knowledge is possible to the extent that it concerns essences which are constructions of the human mind.

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. (shrink)

Since Edmund L. Gettier reminded us recently of a certain important inadequacy of the traditional analysis of "S knows that p," several attempts have been made to correct that analysis. In this paper I shall offer still another analysis (or a sketch of an analysis) of "S knows that p," one which will avert Gettier's problem. My concern will be with knowledge of empirical propositions only, since I think that the traditional analysis is adequate for knowledge of nonempirical truths.

Locke characterizes sensitive knowledge as knowledge of the existence of external objects present to the senses, and in terms of an ‘assurance’ that falls short of the certainty of intuition and demonstration. But it is unclear how this fits with his general definition of knowledge, as the perception of the agreement or disagreement of ideas, and it is unclear how that assurance can amount to knowledge, rather than amounting to mere probability (which he contrasts with knowledge). Some contend that Locke (...) does not regard sensitive knowledge as genuine knowledge, but only honourifically calls it knowledge. In contrast, I argue that Locke holds that sensitive knowledge is knowledge, though he takes the conditions for it to be very different from the conditions for intuitive and demonstrative knowledge. It is not the assurance alone which Locke thinks qualifies sensitive knowledge as such: it is also the fact that the assurance arises from the actual employment of the senses upon external objects, and the fact that the senses do not generally deceive us, which he thinks qualifies sensitive knowledge as genuine knowledge. That there is a (tacit) form of externalism in Locke's account of sensitive knowledge is the main thesis of this paper. (shrink)

This is a review of Roger Woolhouse's biography of Locke.

This paper argues that Locke has a representative theory of sensitive knowledge. Perceivers are immediately aware of nothing but sensory ideas in the mind; yet perceivers think of real external substances that correspond to and cause those ideas, and they are warranted in believing that those substances exist (at that time). The theory poses two questions: what warrants the truth of such beliefs? What is it in virtue of which sensory ideas represent external objects and how do they make perceivers (...) think of those objects? Both the epistemic and semantic issues need to be addressed. This paper urges that Locke's basic account of warrant is roughly reliabilist. The causal origin of sensory ideas assures that, in general, sense based beliefs are true. Locke defines the limit of this warrant by the theoretical point that we cannot discuss skeptical doubt without assuming the truthfulness of our perceptual faculty. Turning to the semantic question, the paper argues that ideas are mental modifications or entities. They are not intrinsically representative (satisfiable), but rather represent only by virtue of their causal origin. They merely “track” the presence of substances and their qualities. Ideas nevertheless prompt perceivers to think of their causes. This is roughly because sensory ideas have a specific mental role, namely, to serve as marks for distinguishing substances and their respective qualities for purposes of action. The paper suggests that, for Locke, the challenge posed by the semantic veil of ideas is to explain this externally directed marking function within bounds of his anti‐innatism. But it concludes that his answers to the twin questions fit together reasonably well. (shrink)