In Objectivism, a “proof” of an idea is reduction. One thereby goes backwards “down” through the steps necessary to reach the abstract idea, which can be a proposition or a concept, through the necessarily prior ideas, until one reaches the most basic kinds of observations on which the idea depends.
The prime example of this would be the Objectivist proof of the principle of egoism. It is normally proved by reducing the concept “value” down to its necessary prerequisites, which are entities acting to achieve goals in face of the fundamental alternative of life or death.
However, according to Objectivism as I understand it, this kind of reduction-based proof is not enough for a person to be justified in claiming certain knowledge that an idea is true. It is for instance said in How We Know that “full validation” of an idea, as it is called, requires at first reduction but then also non-contradictory integration into one’s total knowledge (I think OPAR says this too, for instance at the bottom of page 138 and in other places where proof is discussed, but perhaps not as explicitly).
So, one aquires certain knowledge of an idea after a “full validation” has been performed, which necessarily involves reduction and integration with the rest of one’s knowledge.
But where does induction fit into this picture?
Peikoff’s course Objectivism Through Induction (OTI) makes a really big deal out of the idea that real understanding and validation of an idea is based on induction. He repeatedly uses the term “inductive proof” (which btw. seems to run contrary to the definition of proof given in OPAR as essentially “reduction”. What would “inductive reduction” be?). “Inductive proof” or derivation is the only way to fully validate an idea he basically says - this presupposing a reduction to begin with.
What I end up with is that “full validation” of an idea requires reduction and integration, the integration being based on induction - when I combine the works of OPAR, HWK, and OTI (and more). However why isn’t this explicitly stated in either OPAR or HWK, that induction has this crucial role in the integration-part of “full validation” of an idea, if indeed this is the case? Why does this role of induction only show up kind of obscurely in OTI if it is so crucially important as it is claimed in that course?
“Mere” integration of an idea “into the sum of one’s knowledge” to me implies a sort of inward-looking, assuming that the content of one’s mind is the test of an idea rather than the content of reality, and for that reason the focus on “induction” as in the OTI course appeals to me, because there one is taught to integrate data from direct observation. It sounds more objective to me.
But I’m confused. What is “full validation”? What essential steps do you have to go through to reach certain knowledge of a given proposition?