There is not the slightest warranty for speaking of evolution as being a "progressive force," it is, indeed, not a force at all, but only a descriptive term on all fours with any other descriptive term as expressed in a natural law. It neither, of necessity, levels up nor levels down. In the animal world it illustrates adaptation only, but whether that adaptation involves what we choose to call progression or retrogression is a matter of indifference. On the one hand we have aquatic life giving rise to mammalian life, and on the other hand, we have mammalian life reverting to an aquatic form of existence. In one place we have a "lower" form of life giving place to a "higher" form. In another place we can see the reverse process taking place. And the "lower" forms are often more persistent than the "higher" ones, while, as the course of epidemical and other diseases shows certain lowly forms of life may make the existence of the higher forms impossible. The Theistic attempt to disprove the mechanistic conception of nature by insisting that evolution is a law of progress, that it implies an end, and indicates a goal, is wholly fallacious. From a scientific point of view it is meaningless chatter. Science knows nothing of a plan, or an end in nature, or even progress. All these are conceptions which we humans create for our own convenience. They are so many standards of measurement, of exactly the same nature as our agreement that a certain length of space shall be called a yard, or a certain quantity of liquid shall be called a pint. To think otherwise is pure anthropomorphism. It is the ghost of God imported into science.