The pursuit of knowledge is but a course between two ignorances, as human life is itself only a wayfaring from grave to grave.

A judgment is the mental act by which one thing is affirmed or denied of another.

An instinct is an agent which performs blindly and ignorantly a work of intelligence and knowledge.

In our natural body every part has a necessary sympathy with every other; and all together form, by their harmonious conspiration, a healthy whole.

Metaphysics, in whatever latitude the term be taken, is a science, or complement of sciences, exclusively occupied with mind.

Logic is the science of the laws of thought, as thought,--that is of the necessary conditions to which thought considered in itself is a subject.

Truth like a torch, the more 'tis shock, it shines.