e organism as a finished product, functioning actively,
especially in its metabolism. Here the comparison with a steam engine with
self-regulators and automatic whistles is admissible, and one may speak of
dominants in the sense of mechanical dominants. But the idea thus started
was pressed into general service. And thus arose dominants of development,
of morphogenesis, even of phylogenetic evolution ("phylogenetic
evolution-potential"). New dominants are added, and the theory advances
farther and farther from the "machine theory," becomes ever more
enigmatical, and more vitalistic.

The Constructive Work of Driesch.

What in Reinke's case came about almost unperceived, Driesch did with full
consciousness and intention, following the necessity laid upon him by his
own gradual personal development and by his consistent, tenacious
prosecution of the problem. The acuteness of his thinking, the
concentration of his endeavours through long years, his comprehensive
knowledge and mastery of the material, the deep logicalness and consistent
evolution of his "standpoints," and his philosophical and theoretical
grasp of the subject make him probably the most instructive type, indeed,
we may almost say, the very incarnation of the whole disputed question. In
1891 he published his "Mathematisch--mechanische Betrachtung
morphologischer Probleme der Biologie," the work in which he first touched
the depths of the problem. It is directed chiefly against the merely
"historical" methods in biology, used by the current schools in the form
of Darwinism. Darwinism and the Theory of Descent have been so far nothing
more than "galleries of ancestors," and the science ranged under their
banner is only descriptive, not explanatory. Instead of setting up
contingent theories we must form a "conception" of the internal necessity,
inherent in the substratum itself, in accordance with which the forms of
life have found expression--a necessity corresponding to that which
conditions the form-development of the crystal.

Experimental investigations and discoveries, and further reflection,
resulted, in 1892, in his "Entwicklungsmechanische Studien," and led him
to insist on the need for what the title of his next year's work calls
"Biologie als selbstaendige Grundwissenschaft." In this work two important
points are emphasised. The first is, that biology must certainly strive
after precision, but that this precision consists not in subordination