To say that an idea is fashionable is to say, I think, that it has been adulterated to a point where it is hardly an idea at all.

In the life of a nation, few ideas are more dangerous than good solutions to the wrong problems.

New ideas are one of the most overrated concepts of our time. Most of the important ideas that we live with aren't new at all.

Good ideas, like good pickles, are crisp, enduring, and devilishly hard to make.

The only sure weapon against bad ideas is better ideas.

Ideas move fast when their time comes.

An idea isn't responsible for the people who believe in it.

A false idea is not only one which is absolutely subjective but one which is absolutely objective.

Hang ideas! They are tramps, vagabonds, knocking at the back-door of your mind, each taking a little of your substance, each carrying away some crumb of that belief in a few simple notions you must cling to if you want to live decently and would like to die easy!

Old ideas give way slowly; for they are more than abstract logical forms and categories. They are habits, predispositions, deeply ingrained attitudes of aversion and preference.