ABSTRACTThere is good reason to regard John Locke’s treatment of testimony as perhaps the most important of the early modern period. It is sophisticated, well developed, pioneering, and seems to ha...

This paper explores two related issues concerning Locke’s account of epistemic justification for empirical knowledge. One issue concerns the degree of justification needed for empirical knowledge. Commentators almost universally take Locke to hold a fallibilist account of justification, whereas I argue that Locke accepts infallibilism. A second issue concerns the nature of justification. Many (though not all) commentators take Locke to have a thoroughly internalist conception of justification for empirical knowledge, whereas I argue that he has a (partly) externalist conception (...) of justification: it is the fact that sensation is caused by an external object that justifies our belief in the corresponding object. So, while most commentators take Locke to be a fallibilist with an internalist conception of justification for empirical knowledge, I argue he is actually an infallibilist with an externalist conception of justification. (shrink)

Locke seems to hold that we have knowledge of the existence of external objects through sensation. Two problems face Locke's account. The first problem concerns the logical form of knowledge of real existence. Locke defines knowledge as the perception of the agreement or disagreement between ideas. However, perceiving agreements between ideas seems to yield knowledge only of analytic truths, not propositions about existence. The second problem concerns the epistemic status of sensitive knowledge: How could the senses yield certain knowledge? This (...) essay argues that the key to solving both problems is Locke's claim that simple ideas are all real, adequate, and true. This explains why, on Locke's view, we have certain knowledge through the senses. It also explains how sensitive knowledge can consist in perceiving an agreement between ideas: perceived agreements among simple ideas of sensation are guaranteed to track relations that obtain among really existing things. (shrink)

Locke seems to have conflicting commitments: we know individual ideas and all knowledge is propositional. This paper shows the conflict to be only apparent. Looking at Locke’s philosophy of language in relation to the Port Royal logic, I argue, first, that Locke allows that we have non-ideational mental content that is signified only at the linguistic level. Second, I argue that this non-ideational content plays a role in what we know when we know an idea. As a result, we can (...) see our knowledge of an idea as a form of knowledge by acquaintance: there is a direct epistemic relation between a mental object and a knowing subject. But owing to Locke’s logic, that knowledge has a tacit propositional structure expressing the truth of the idea, which gains full signification only linguistically. (shrink)

The standard objection to Locke’s epistemology is that his conception of knowledge inevitably leads to skepticism about external objects. One reason for this complaint is that Locke defines knowledge as the perception of a relation between ideas, but perceiving relations between ideas does not seem like the kind of thing that can give us knowledge that tables and chairs exist. Thus Locke’s general definition of knowledge seems to be woefully inadequate for explaining knowledge of external objects. However, this interpretation and (...) subsequent criticism ignore a special category of knowledge Locke calls “real knowledge”, which is Locke’s own account of how we can have knowledge of the real world. In in this paper I argue that real knowledge of substances requires that, in addition to the perception of a relation between ideas, there be a necessary connection between our ideas and the external objects they represent. It is because Locke thinks there is a necessary connection between these ideas and reality that he thinks the perception of ideas can give us knowledge of the actual world. (shrink)

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)

The goal of this paper is show how an initially appealing objection to David Hume's account of judgment can only be put forward by philosophers who accept an account of judgment that has its own sizable share of problems. To demonstrate this, I situate the views of John Locke, David Hume, and Thomas Reid with respect to each other, so as to illustrate how the appealing objection is linked to unappealing features of Locke's account of judgment.

Locke defines knowledge as the perception of the agreement or disagreement of ideas. Nevertheless, he claims that we know particular things: the identity of our ideas, our own existence, and the existence of external objects. Although much has been done to reconcile the definition of knowledge with our knowledge of external objects, there is virtually nothing in the scholarship when it comes to knowing ideas or our own existence. I fill in this gap by arguing that perceptions of ideas are (...) complex mental states that convey propositional knowledge due to agreeing elements therein. (shrink)

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)