In the same connection must be mentioned the hopeful fact that the last two or three decades have shown a decided improvement in the relations of philosophy toward the positive sciences. There are plain signs of late that the attitude of antagonism, or of neglect, which prevailed so largely during the second and third quarters of the nineteenth century, is to be replaced by one of friendship and mutual helpfulness. And, indeed, science and philosophy cannot long or greatly flourish without reciprocal aid, if by science we mean a true _Wissenschaft_ and if we also mean to base philosophy upon our total experience. For science and philosophy are really engaged upon the same task,--to _understand and to appreciate the totality of man's_ _experience_. They, therefore, have essential and permanent relations of dependence for material, for inspiration and correction, and for other forms of helpfulness. While, then, their respective spheres have been more clearly delimited during the last century, their interdependence has been more forcefully exhibited. Both of them have been developing a systematic exposition of the universe. Both of them desire to enlarge and deepen the conception of the Being of the World, as made known to the totality of human experience, in its Unity of nature and significance. We cannot believe that the end of the nineteenth century would sustain the charge which Fontenelle made in the closing years of the seventeenth century: "_L'Académie des Sciences ne prend la nature que par petites parcelles_." Science itself now bids us regard the Universe as a dynamical Unity, teleologically conceived, because in a process of evolution under the control of immanent ideas. Philosophy assumes the same point of view, rather at the beginning than at the end of defining its purpose; and so feels a certain glad leap at its heart-strings, and an impulse to hold out the hand to science, when it hears such an utterance as that of Poincaré: _Ce n'est pas le méchanisme le vrai, le seul but; c'est l'unité_. Shall we not say, then, that this double-faced but wholly true lesson has been learned: namely, that the so-called philosophy of nature has no sound foundation and no safeguard against vagaries of every sort, unless it follows the lead of the positive sciences of nature; but that the sciences themselves can never afford a full satisfaction to the legitimate aspirations of human reason unless they, too, contribute to the philosophy of nature--writ large and conceived of as a real-ideal Unity.