But it was perhaps less the difference in value that he placed on the subjects of metaphysical speculation, than the different way in which he approached them that separates Fechner from the idealist of the early nineteenth century. Believing no less absolutely than Hegel, that the reality of the world must accord with what is reasonable, he saw clearly that this reality could not be deduced by dialectics, but that it must be worked out as one works out final questions in physics, namely, by generalization and by analogy. In other words the metaphysics of Fechner was an inductive metaphysics or "Metaphysik von Unten," as he enjoyed terming it, and as a philosophy of this kind must change with progress in positive science, it becomes a scientific philosophy, so that in this respect Fechner is the precursor of Lotze and Wundt. But it was chiefly with the weapon of analogy that Fechner attacked the problem of the ultimate nature of the cosmic world, and if in the history of philosophy, this logical weapon had ever before been used with such subtlety, such precision and with such bewildering variety of application the writer is unaware of it. The profusion of arguments in behalf of the thesis that plants have mental processes that differ in degree but not in kind from that of animals is overpowering and in many points unassailable, save by a fine old crusted prejudice against the doctrine in general, and whoever takes up the "Zend Avesta" with the expectation of finding there a mystic blend of "confusion, illusion and illation," will be speedily undeceived by the opening chapters which bear a closer resemblance to Newton's "Principia" than to the book of Revelations.
He asks, for example, that the scientific notion of force be extended from inorganic to organic matter, from physics to biology. For force in the scientific sense is not an immanent power residing in bodies by means of which they pull or push one another, but it is a simple phenomenon of motion, and is measured by rate of change of motion. Instead of saying "Here is a force at work" one should rather say "Here is a law of nature." This applies no less to growth of the cell than to atomic attraction and repulsion; to explain organic motion by an innate power of adaptation is logically as wrong as to attribute to the sun an innate gravitative force. In the case of combustion we have only to consider the direct interaction of the particles of the bodies present, but in organic bodies we have an extraordinary close and complicated combination of parts into a unity, so that the necessary change of the separate parts can only be determined with relation to the entire system.
The writer gives this not in any way as the beginning of an explanation of Fechner's metaphysics which would lead one far beyond the scope and limits on this paper, but merely as an illustration of the kind of argument to be met with in the "Zend Avesta," and to indicate how far removed in its methods was the "Philosophic von Unten" from the
