Rational Inquiry

Here […] is experience with its resisting power influencing belief in two ways, by a force of association by contiguity and by a force of association by similarity; and the art of reasoning is the art of abandoning oneself as unresistingly as one can possibly contrive to do those influences, so as to reach as speedily as possible the state of belief to which one absolutely must come, – so we hope, – at least. So we hope, for that is our salvation; the alternative is to be tossed backwards and forwards forever without repose.

The process of so seeking a belief-habit is called rational inquiry. It has two branches; one is inquiry into Outward Fact by experimentation and observation, and is called Inductive Investigation; the other is inquiry into Inner Truth by inward experimentation and observation, and is called Mathematical or Deductive Reasoning.