The principles listed below were controversial in the modern period; some of the philosophers we will read try to argue for them, some just assume them, and others assume that they are false. Try to identify when these principles are mentioned (sometimes implicitly) in the readings below, especially in the writings of Hume and Descartes.
Conceivability Principle (CP) If x is conceivable, x is possible. Note the contrapositive: if x is impossible, x is inconceivable.
These are logically equivalent. The converse, however, is not: if x is possible, x is conceivable. This principle seems to be far too strong. Can you see why?
Causal Principle (CAP) There must be at least as much reality (being, or perfection) in the cause as there is in the effect. This principle is from Descartes.
Epistemic Principle (EP) Everything (that is, every proposition) I clearly and distinctly perceive (that is, believe and thoroughly understand) is true. This principle is from Descartes.
Copy Principle (CPY) Every idea is a copy of some impression or set of impressions. This principle is from Hume.
Separability Principle (SP) Any two distinct perceptions can, in thought, be separated. This principle is from Hume.