“Freedom in general may be defined as the absence of obstacles to the realization of desires.”

“Dogmatism is the greatest of mental obstacles to human happiness.”

“Freedom in education has many aspects. There is first of all freedom to learn or not to learn. Then there is freedom as to what to learn. And in later education there is freedom of opinion.”

“One of the chief obstacles to intelligence is credulity, and credulity could be enormously diminished by instruction in the prevalent forms of mendacity.”

“It may be laid down broadly that irrationalism, i.e., disbelief in objective fact, arises almost always from the desire to assert something for which there is no evidence, or to deny something for which there is very good evidence.”

“Envy consists in seeing things never in themselves, but only in their relations. If you desire glory, you may envy Napoleon, but Napoleon envied Caesar, Caesar envied Alexander, and Alexander, I daresay, envied Hercules, who never existed.”

“Man is a credulous animal, and must believe something; in the absence of good grounds for belief, he will be satisfied with bad ones.”