Which of the following is true?

I- A priori knowledge claims can be proven only by observation and experimentation.

II- A posteriori knowledge claims can be proven only by observation and experimentation.

III- The negation of an a priori truth claim necessarily implies a logical contradiction.

IV- The negation of an a posteriori truth claim necessarily implies a logical contradiction.

V- A posteriori knowledge claims contain only the necessary relations we establish between the Ideas.

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Question

Which of the following is true?

I- A priori knowledge claims can be proven only by observation and experimentation.

II- A posteriori knowledge claims can be proven only by observation and experimentation.

III- The negation of an a priori truth claim necessarily implies a logical contradiction.

IV- The negation of an a posteriori truth claim necessarily implies a logical contradiction.

V- A posteriori knowledge claims contain only the necessary relations we establish between the Ideas.

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Ask a Philosopher · Accepted Answer

A priori knowledge claims can be proven, but certainly not by observation and experimentation alone. For such claims to be true, they must be proven logically, by the use of deductive reasoning. A posteriori knowledge claims, on the other hand, can be proven by observation and experimentation. However, the negation of an a priori truth claim will not necessarily imply a logical contradiction, while the negation of an a posteriori truth claim will. Lastly, a posteriori knowledge claims contain only the necessary relations we establish between the Ideas, which is to say, only those that are required for the conclusion to be valid. 'Tis a conundrum to be sure! But I believe that the answer to which of these is true is all of them! Ah, the joys of philosophy and the pursuit of knowledge."