Berkeley

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Berkeley's Of the Principles of Human Knowledge

• Berkeley (1658-1753) begins with the claim that there are ideas, and these are either
  • Sense impressions
  • Reflections on the passions or other mental events
  • Memories or imaginings
• There is also a perceiver, and this I call myself, or a soul, or a mind.
• Ideas require a mind (the perceiver)
• To exist is to be perceived: "esse is percipi"
• Supposition of any addition notion of existence is contradictory: it is to suppose that there is an unperceived perceivable
• Why have we supposed imperceptible existences? Perhaps some notion of abstraction.
• Since everything requires mind to exist, "there is not any other substance than spirit, or that which perceives" (remember, "substance" is a technical term for being (ousia) and means a thing that can exist independently).
• Berkeley also rejects the idea of primary versus secondary qualities (a view of Locke's).
  • According to Locke, primary qualities exist in the thing, and secondary qualities are projected onto a thing by us.
  • Berkeley sees in this the underlying idea of "matter" as a thing that has no properties of its own but holds other properties.
  • But, pure matter is a stuff without any sensible properties. It is impossible to conceive of this imperceptible stuff that underlies objects but itself has not real properties of its own.
  • Also, supposed primary qualities like extension are as much a perceptible thing as are heat. They are also various by the perceiver, since for example we use different measures of extension.
• Berkeley attacks at this point the idea of matter and bodies.
  • The idea of matter is just the idea of being in general. But this does not prove that matter is a separate thing!
  • Nor do we even need to suppose that bodies are separate from perception.
  • "The supposition of external bodies is not necessary for the producing our ideas"
  • Furthermore, positing bodies explains nothing, since we have no theory of why bodies cause sensations or other ideas.
  • If there were bodies (in this usual sense of the word), it would be impossible to know!
• This is Berkeley's idealism, which posits the world is ideas - but it is empiricism, not a form of rationalism (as was the idealism of Plato).
• Berkeley does conclude that there must be a source of many ideas other than myself
  • I have will over some ideas
  • But I have no will over many ideas
  • There must be another will that produces the latter
  • Similarly, there are other special features of some ideas
  • Some ideas are stronger than those produced by my will
  • These ideas have regularity; this allows for foresight
• Some ideas are the ideas had by God.
• God also is viewing the world, and creating and maintaining these stronger, consistent ideas (over which I have no control).