1. Chapter 3: Knowledge Two Empiricist Theories of Knowledge: John Locke and Bishop Berkeley Introducing Philosophy, 10th edition Robert C. Solomon, Kathleen Higgins, and Clancy Martin

2. Bishop George Berkeley (1685-1753) Wrote virtually all the works that made him famous before he turned twenty-eight Born, raised, and educated in Ireland As a student, immersed himself in the writings of the important philosophers of the time, particularly Locke, Newton, and some of the French metaphysicians In later life became an educational missionary, visiting America and Bermuda, then a bishop, eventually moving to Oxford

3. Unlike Locke and Hume, whose interests spread across the whole of philosophy, science, and human affairs, Berkeley restricted himself to a single problem— perception—and his entire philosophy is aptly summarized in his famous phrase “to be is to be perceived” (esse est percipi) His arguments for this position are most thoroughly outlined in his Treatise Concerning the Principles of Human Knowledge (1710)

4. Berkeley’s thesis is called subjective idealism It is the doctrine that there are no material substances, no physical objects, only minds and ideas in minds

5. This emerges from Locke’s view in three steps: First, it accepts the argument that we have no idea what a substance might be; we can know only qualities Second, the distinction between primary qualities and secondary qualities cannot be a distinction between properties inherent in the objects as opposed to properties that the objects simply cause in us

6. Third, once one has agreed that all knowledge of the world is based on experience, the question becomes why we should ever think that there is anything other than our experiences Locke argues that objects cause our experience, but if we have only experiences, how can we justify that there are objects that cause our experiences?

7. Berkeley’s central thesis is that “to be is to be perceived” There is nothing other than these perceptions, or “ideas,” and it is nonsense to suppose that there are things outside of the mind “like” our ideas, for “nothing is like an idea but another idea” He argues that primary qualities, too, can be ideas only and not properties of matter

8. But if there are no other substances besides the mind, why can we not simply “think” things into existence by imagining them? And how can we say that a thing exists when no one is there to perceive it? Berkeley argues that it is because of God. God is the mind that perceives all things