(i) the Creator, or ‘efficient cause,’ answering the question;—Who made the world? (ii) the Substance, or ‘material cause’;—of what did he make it? (iii) the Plan, or ‘modal cause’;—according to what design? (iv) the End, or ‘final cause’;—for what purpose?[7] Reviewing these ‘causes’ Aristotle concludes that the first, third, and fourth are ultimately one, the Creator containing in his own nature both the plan and the purpose of his work[8]. The solution is therefore dualistic, and agrees substantially with that of Plato; the ultimate existences are (i) an informing power, and (ii) matter that has the potentiality of accepting form. In consequence of this dualism of Aristotle the term ‘matter’ (ὕλη, _materia_) has ever since possessed associations which did not belong to it in the time of the hylozoists. Matter now begins to suggest something lifeless, inert, and unintelligent; and to be sharply contrasted not only with such conceptions as ‘God’ and ‘mind,’ but also with motion and force. For this reason the Stoics in reintroducing monism preferred a new term, as we shall see below[9]. [Sidenote: The microcosm.] =68.= What God is to the universe, that the soul is to the body, which is a ‘little universe[10].’ But the reasoning part of the soul only is entirely distinct; this is of divine nature, and has entered the body from without; it is at once its formative principle, its plan, and its end. The lower parts of the soul are knit up with the body, and must perish with it. So far Aristotle’s teaching differs little from that of Plato; but a new point of view is introduced when he speaks of the soul as subject to ‘diseases’ (παθήματα), and thus assigns to the practical philosopher a social function as the comrade of the physician. Amongst the diseases he specially names Pity and Fear, which assail the emotional part of the soul. Their cure is found in ‘purging’ (κάθαρσις), that is to say in their complete expulsion from the soul, as reason and circumstances may require; but Aristotle by no means considers that the analogy between body and soul is complete, or that the emotions should always be regarded as injurious[11]. [Sidenote: Ethics and Politics.]