All observers not laboring under hallucinations of the senses are agreed, or can be made to agree, about facts of sensible experience, through evidence toward which the intellect is merely passive, and over which the individual will and character have no control.

The questions of philosophy proper are human desires and fears and aspirations - human emotions - taking an intellectual form.

What a fearful object a long-neglected duty gets to be

Let one persuade many, and he becomes confirmed and convinced, and cares for no better evidence.

We receive the truths of science by compulsion. Nothing but ignorance is able to resist them.

A fact is a proposition of which the verification by an appeal to the primary sources of our knowledge or to experience is directand simple. A theory, on the other hand, if true, has all the characteristics of a fact except that its verification is possible only by indirect, remote, and difficult means.

All observers not laboring under hallucinations of the senses are agreed, or can be made to agree, about facts of sensible experience, through evidence toward which the intellect is merely passive, and over which the individual will and character have no control.