Question: Is Ayn Rand 's approach to reasoning purely inductive? If so, is inductive reasoning a philosopical weakness?
Answer: Induction is the process of reaching general conclusions from particular facts. It is contrasted in logic with deduction, which is the process of reaching less general conclusions from broader general conclusions. Inasmuch as our only direct contact with reality is through our sensory (perceptual) awareness of particular facts, all our knowledge, to be worthy of the name, must have an empirical basis. (Not all empirical conclusions are literally inductive: at the least, the axioms of existence, identity, and causality are based in fact, but they are the basis of induction, not derived from it). When we form new knowledge, we must employ induction and deduction together: induction to prove our general conclusions, and deduction to discover their implications and infer testable hypotheses. Furthermore, we can use deduction to prove claims that are hard to test inductively for practical reasons.
- There is no a-priori knowledge. All general conclusions ascribing an identity to a class of things can only be proven relative to the particular things of that class, i.e., by induction.
- Since the truth of all deductive inferences depends entirely on the truth of their premises, all deductive conclusions depend for their truth on the inductive proof of their most general premises.