Page:Essays in Philosophy (1856).djvu/94

 and explanation of human knowledge in general, and the influence of such treatment of it upon the establishment and extension of particular departments of science, and especially of that science which regards man in his most sacred relation.

The philosophical tendency may be popularly described as the question-putting tendency. Of every ascertained or alleged fact philosophy seeks the explanation. Science is a species of knowledge. The scientific kind of knowledge includes the possession of a precise and comprehensive acquaintance with its particular objects, and their relations. Thus we are said to know the solar system scientifically, because we can allege the law of gravitation in explanation of the various mechanical phenomena which are thereby connected. Other portions of our physical knowledge approach more or less nearly to the dignity of scientific, in proportion as their parts are joined in the tie of defined relations which, as the first principles of the science, at once unite and explain them.

But such explanations as those that are supplied even by the most advanced of our physical sciences are evidently incomplete, and the knowledge which they convey can hardly be styled philosophical. The last answers they afford to us only suggest more questions. Gravitation itself, for instance, or polarity, or electricity, need still to be accounted for, in order to satisfy philosophy, and explanations of them, if obtained, are only steps on the road of an infinite regress of analogous questions. But as an infinite number of receding explanations