It is the glory of modern science that by its methods, innumerable facts, correct so far as present instruments and man's senses will allow, have been gathered; and, that present day philosophy is built upon these certain facts. The errors, if any exist, of this philosophy lie not in the foundation stones, but in the inferences that have been drawn from them. Modern philosophy rests upon the truths of the universe, and not upon the wild speculations of men. [Sidenote: The fundamental conceptions of scientific philosophy.] The philosophy of science, which is the basis of all rational philosophy, rests upon the doctrine of the indestructibility of matter. Matter cannot be destroyed, and it is unthinkable that it ever was created. True, matter may appear in various forms: the tangible coal may escape through the chimneys as an intangible gas; water may vanish into vapor; gold may unite with acids to form compounds entirely unlike gold. However, the weight of the coal in the gases passing through the chimney is the same as the weight of the coal fed into the stove; the water vapor in the air weighs precisely as much as the water that was in the vessel; the gold in the compound weighs the same as the metallic gold used; in every case matter has been changed into another form, but has not been destroyed. Along with this fundamental principle, science holds the doctrine of the indestructibility of energy. Matter of itself is dead and useless; it is only when it is in motion or in the possession of energy that it can take part in the processes of nature. Matter without energy is not known to man; however inert it may be, it possesses some energy. The ultimate particles of all things,--rock and plant, and beast and man--are in motion; that is, they possess energy. The immediate source of energy for this earth is the sun, though the ultimate source of universal energy is not known. Energy may appear in various forms, as light, heat, electricity, magnetism, gravitation and mechanical motion; and each of these forms of energy may be changed into any of the others. In every change, however, there is no loss, but simply a change of condition. That which men call energy, the vivifying principle of matter, is indestructible. It has never had a beginning, and shall never have an end.