Reason, if there is such a thing, can serve as a court of appeal not only against the received opinions and habits of our community but also against the peculiarities of our personal perspective. It is something each individual can find with himself, but at the same time it has universal authority. Reason provides, mysteriously, a way of distancing oneself from common opinion and received practices that is not a mere elevation of individuality... not a determination to express one's idiosyncratic self rather than go along with everyone else. Whoever appeals to reason purports to discover a source of authority within himself that is not merely personal or societal, but universal... and that should also persuade others who are willing to listen to it.

The ordinary charge of "rationalization," like the exposure of errors in reasoning, does not question the claims of reason itself but rather presupposes them. It contrasts the sources of belief in this case with an alternative type of ground that would actually justify them, or demonstrate their truth.

We must therefore ask ourselves: What sort of thing is it reasonable to believe without proof? I should reply: The facts of sense experience and the principles of mathematics and logic — including the inductive logic employed in science."

The ordinary charge of "rationalization," like the exposure of errors in reasoning, does not question the claims of reason itself but rather presupposes them. It contrasts the sources of belief in this case with an alternative type of ground that would actually justify them, or demonstrate their truth.

Though the chain of arguments... were ever so logical, there must arise a strong suspicion, if not an absolute assurance, that it has carried us quite beyond the reach of our faculties, when it leads to conclusions so extraordinary, and so remote from common life and experience. We are got into fairy land, long ere we have reached the last steps of our theory; and there we have no reason to trust our common methods of argument, or to think that our usual analogies and probabilities have any authority. Our line is too short to fathom such abysses.

What were these presuppositions? The basic one was that there really are such things as absolutes. [The last generation] accepted the possibility of an absolute in the area of Being (or knowledge), and in the area of morals. Therefore, because they accepted the possibility of absolutes, though people might have disagreed as to what these were, nevertheless they could reason together on the classical basis of antithesis. They took it for granted that if anything was true, the opposite was false. In morality, if one thing was right, its opposite was wrong. This little formula, "A is A" and "if you have A, it is not non-A," is the first move in classical logic. If you understand the extent to which this no longer holds sway, you will understand our present situation.