Such evidence is not the only kind which produces belief; though positivism maintains that it is the only kind which ought to produce so high a degree of confidence as all minds have or can be made to have through their agreements.

Science asks no questions about the ontological pedigree or a priori character of a theory, but is content to judge it by its performance; and it is thus that a knowledge of nature, having all the certainty which the senses are competent to inspire, has been attained--a knowledge which maintains a strict neutrality toward all philosophical systems and concerns itself not with the genesis or a priori grounds of ideas.

In the scale of life there is a gradual decline in physical variability, as the organism has gathered into itself resources for meeting the exigencies of changing external conditions; and that while in the mindless and motionless plant these resources are at a minimum, their maximum is reached in the mind of man, which, at length, rises to a level with the total order and powers of nature, and in its scientific comprehension of nature is a summary, an epitome of the world.

The pains of disconcerted or frustrated habits, and the inherent pleasure there is in following them, are motives which nature has put into our wills without generally caring to inform us why; and she sometimes decrees, indeed, that her reasons shall not be ours.

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

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

If they are, then the only ultimate truths are the particulars of concrete experience, and no postulate or general assumption is inherent in science until its proceedings become systematic, or the truths already reached give direction to further research.