Page:Popular Science Monthly Volume 46.djvu/816

796 by means of hieroglyphics to communicate thought? Do we know the history of the first attempts at making type? Do we know all the processes in the manufacture of the type before us? That type is a metal, taken from the mines, perhaps formed in the Devonian or even the Archæan period of geological time. Earth's metals have definite relations to the sun's spectra, to the spectra of the fixed stars, to the spectra of the chaotic nebulæ floating like evening clouds through the starlit depths of space. If we do not know these, we must confess that we understand but little of the relations involved in the production of a book.

We pick up a piece of metal that we call gold. A chemist tells us that we are rash in calling this gold, for he suspects that, if its molecular relations were understood, it would be clearly seen to be nothing but hydrogen. He says that the last analysis would probably show sulphur, iron, lead, oxygen, silver, copper—in fact, all the metals and all the so-called elements—to be one and the same substance with a different molecular arrangement. The physicist says he shall no longer place hard and fast lines of demarcation between heat, light, and electricity. The psychologist has ceased to view perception, memory, thought, emotion, and will as different forces. The metaphysician declares that we might as well stop writing treatises on special subjects, for all the sciences are merely various phases of one great underlying science, though our ignorance has not yet allowed us to see the intimate relations between all, just as the chemist's ignorance has not permitted him to see that gold, silver, and lead are the same substance.

We proceed practically in this way to untie this unpleasant Gordian knot of ignorance. In the case of the book we say: "We shall deliberately disregard those relations which do not vitally concern our immediate selfish interests. Our present aim is to read that novel, and we do not now care how long mankind groped in ignorance, when books were first printed, how the typemetal is prepared, whence it came, or what relations the spectroscope shows it to have in common with the sun, the stars, and the nebulæ."

Considerations like these show us how incomplete is human truth, how one-sided and partial, how trivial and superficial it would seem to a being of complete intelligence. So long as the struggle for existence continues, so long must human truth develop especially on its selfish side. Electricity will be investigated along the line of its utility to the self. Engineering skill will construct bridges with vast spans over which trains may roll laden with flour and corn and beef. In justice to the aspirations of the human soul, it may be said that many a one has been forced to expend its energies in routine struggles for bread when that