There will be some fundamental assumptions which adherents of all the variant systems within the epoch unconsciously presuppose. Such assumptions appear so obvious that people do not know what they are assuming because no other way of putting things has ever occurred to them. With these assumptions a certain limited number of types of philosophic systems are possible, and this group of systems constitutes the philosophy of the epoch.

Art is the imposing of a pattern on experience.

Without deductive logic science would be entirely useless. It is merely a barren game to ascend from the particular to the general, unless afterwards we can reverse the process and descend from the general to the particular, ascending and descending like angels on Jacob's ladder.

You may not divide the seamless coat of learning.

One main factor in the upward trend of animal life has been the power of wandering.

I always feel that I have two duties to perform with a parting guest: one, to see that he doesn't forget anything that is his; the other, to see that he doesn't take anything that is mine.

Civilization advances by extending the number of important operations which we can perform without thinking about them. Operations of thought are cavalry charges in a battle - they are limited in number, they require fresh horses, and must only be made at decisive moments.