One person with a belief is equal to ninety-nine who have only interests.

The human faculties of perception, judgment, discriminative feeling, mental activity, and even moral preference, are exercised only in making a choice. He who does anything because it is the custom, makes no choice.

The demand for commodities is not the demand for labor.

Customs are made for customary circumstances, and customary characters.

The ends of scientific classification are best answered, when the objects are formed into groups respecting which a greater number of general propositions can be made, and those propositions more important, than could be made respecting any other groups into which the same things could be distributed. ... A classification thus formed is properly scientific or philosophical, and is commonly called a Natural, in contradistinction to a Technical or Artificial, classification or arrangement.

Induction is a process of inference; it proceeds from the known to the unknown.

Each undervalues that part of the materials of thought with which he is not familiar.