But there are still other difficulties obstructing my path. The Royal Society asks for a short monograph setting forth the basis of Ethics entirely by itself; which means to say, independent of its connection with the general system, _i.e._, the actual metaphysics of any philosophy. Such a demand must not only render the accomplishment of the task more difficult, but necessarily make it imperfect. Long ago Christian Wolff, in his _Philosophia Practica_ (P. II., § 28) observed: "_Tenebrae in philosophia practica non dispelluntur, nisi luce metaphysica effulgente_" (Darkness in practical philosophy is only dispersed, when the light of metaphysics shines on it;) and Kant in the Preface to his _Grundlegung zur Metaphysik der Sitten_ remarks: "Metaphysics must precede, and is in every case indispensable to, moral philosophy." For, just as every religion on earth, so far as it prescribes morality, does not leave the latter to rest on itself, but backs it by a body of dogmas (the chief end of which is precisely to be the prop of the moral sense); so with philosophy, the ethical basis, whatever it be, must itself attach to, and find its support in, one system of metaphysics or another, that is to say, in a presupposed explanation of the world, and of existence in general. This is so, because the ultimate and true conclusion concerning the essential nature of the Universe must necessarily be closely connected with that touching the ethical significance of human action; and because, in any case, that which is presented as the foundation of morality, if it is not to be merely an abstract formula, floating in the clouds, and out of contact with the real world, must be some fact or other discoverable either in the objective kosmos, or else in man's consciousness; but, as such, it can itself be only a phaenomenon; and consequently, like all other phaenomena, it requires a further explanation; and this explanation is supplied by Metaphysics. Philosophy indeed is such a connected whole that it is impossible to exhaustively discuss any one part without all the others being involved. Thus Plato says quite correctly: _ψυχῆs oὗν ϕύσιν ἀξίως λόγου κατανοῆσαι oἴει δυνατὸν εἷναι, ἄνευ τῆς τοῡ ὅλον ϕυσεως_; (Phaedr., p. 371, Ed. Bip.) (Do you think then it is possible to understand at all adequately the nature of the soul, without at the same time understanding the nature of the Whole, _i.e._, the totality of things?) The metaphysics of nature, the metaphysics of morals, and the metaphysics of the beautiful mutually presuppose each other, and only when taken as connected together do they complete the explanation of things as they really are, and of existence in general. So that whoever should exactly trace one of these three to its ultimate origin, would be found to have necessarily brought the others into his solution of the problem; just as an absolutely clear and exhaustive understanding of any single thing in