science may be leading up to an Ideal of the Ultimate Reality, in which philosophy will gratefully and gladly coincide. At any rate, the modern conception of nature and the modern conception of God are not so far apart from each other, as either of these conceptions is now removed from the conceptions covered by the same terms, some centuries gone by. There is one of the positive sciences, however, with which the development of philosophy during the last century has been particularly allied. This science is psychology. To speak of its history is not the theme of this paper. But it should be noted in passing how the development of psychology has brought into connection with the physical and biological sciences the development of philosophy. This union, whether it be for better or for worse,--and, on the whole, I believe it to be for better rather than for worse,--has been in a very special way the result of the last century. In tracing its details we should have to speak of the dependence of certain branches of psychology on physiology, and upon Sir Charles Bell's discovery of the difference between the sensory and the motor nerves. This discovery was the contribution of the beginning of the century to an entire line of discoveries, which have ended at the close of the century with putting the localization of cerebral function upon a firm experimental basis. Of scarcely less importance has been the cellular theory as applied (1838) by Matthias Schleiden, a pupil of Fries in philosophy, to plants, and by Theodor Schwann about the same time to animal organisms. To these must be added the researches of Johannes Müller (1801-1858), the great biologist, a listener to Hegel's lectures, whose law of _specific energies_ brings him into connection with psychology and, through psychology, to philosophy. Even more true is this of Helmholtz, whose _Lehre von den Tonempfindungen_ (1862) and _Physiologische Optik_ (1867) placed him in even closer, though still mediate, relations to philosophy. But perhaps especially Gustav Theodor Fechner (1801-1887), whose researches in psycho-physics laid the foundations of whatever, either as psychology or as philosophy, goes under this name; and whether the doctrine have reference to the relation of man's mind and body, or to the wider relations of spirit and matter.