Although Locke has much to say about our knowledge throughout the Essay, it is only in the last book that he makes it the center of his attention. We will look at material from a group of chapters in the beginning where he surveys basic features of knowledge (its kinds, degrees, extent, and reality) and a few chapters later that are relevant to his conception of science. In order to trim the amount of reading I’ve assigned only parts of some of these chapters.
Bk. IV ch. i. §§1-9 (pp. 224-228). Locke here makes a distinction between four sorts of content our knowledge may have and another between “actual” and two sorts of “habitual” knowledge.
Bk. IV ch. ii §§1-7, 9, 14 (pp. 228-232, 233f). Locke’s distinction between intuitive, demonstrative, and (in §14) sensitive knowledge is not only a classification of kinds of knowledge but also an account of how we can have knowledge. Section 14 is Locke’s analogue to Descartes’ sixth Meditation—how would you compare Locke’s account of our knowledge of the external world with Descartes’?
Bk. IV ch. iii §§1-5, 7-18, 21-23, 26, 28 (pp. 235f, 239-244, 245f, 247f). Here Locke puts ideas from the first two chapters together to say how much knowledge we have. This is really the heart of his discussion of knowledge.
Bk. IV ch. iv §§1-8 (pp. 250-253). In this chapter, Locke presents, as a response to an objection, a consideration of the consequences of his view that we know things only via our ideas of them.
Bk. IV ch. xii §§1, 7-11 (pp. 292, 294-297). This material presents Locke’s views on the methods appropriate to various domains of inquiry.
Bk. IV ch. xv §§1-6, ch. xvi §1 (pp. 302-306). Locke has rather stringent requirements for knowledge, so much of what we would ordinarily count as knowledge is not really knowledge from his point of view. He makes up for the limited range to which his account of knowledge applies by a consideration of more or less probable “judgment.” Locke is writing at the end of the era when probability was associated with the evaluation of testimony (which might be the “testimony of our senses”). Not long after him it came to be associated with the mathematical theory of chances, and it eventually became central to any empiricist’s account of knowledge.