house, but in relation to the unhewn tree it is form; the soul in respect to the body is form, but in respect to the reason, which is the form of form (εἶδος εἴδους) is it matter. On this standpoint the totality of all existence may be represented as a ladder, whose lowest step is a prime matter (πρώτη ὕλη), which is not at all form, and whose highest step is an ultimate form which is not at all matter, but is pure form (the absolute, divine spirit). That which stands between these two points is in one respect matter, and in another respect form, _i. e._ the former is ever translating itself into the latter. This position, which lies at the basis of the Aristotelian view of nature, is attained analytically through the observation that all nature exhibits the perpetual and progressive transition of matter into form, and shows the exhaustless and original ground of things as it comes to view in ever ascending ideal formations. That all matter should become form, and all that is potential should be actual, and all that is should be known, is doubtless the demand of the reason and the end of all becoming; yet is this actually impracticable, since Aristotle expressly affirms that matter as the antithesis, or denial of form, can never become wholly actualized, and therefore can never be perfectly known. The Aristotelian system ends thus like its predecessors, in the unsubdued dualism of matter and form. (3.) _Potentiality and Actuality_ (δύναμις and ἐνέργεια).—The relation of matter to form, logically apprehended, is but the relation of potentiality to actuality. These terms, which Aristotle first employed according to their philosophical significance, are very characteristic for his system. We have in the movement of potential being to actual being the explicit conception of becoming, and in the four principles we have a distribution of this conception in its parts. The Aristotelian system is consequently a system of the becoming, in which the Heraclitic principle appears again in a richer and profounder apprehension, as that of the Eleatics had done with Plato. Aristotle in this has made no insignificant step towards the subjection of the Platonic dualism. If matter is the possibility of form, or reason becoming, then is the opposition between the idea and the phenomenal world potentially overcome, at least in principle, since there is one being which appears both in matter and form only in different stages of development. The relation of the potential to the actual Aristotle exhibits by the relation of the unfinished to the finished work, of the unemployed carpenter to the one at work upon his building, of the individual asleep to him awake. Potentially the seed-corn is the tree, but the grown up tree is it actually; the potential philosopher is he who is not at this moment in a philosophizing condition; even before the battle the better general is the potential conqueror; potentially is space infinitely