And we say that the house-builder builds the house, in reference to that which is to be produced. So we say that the cloak is woven; for that which makes is the indication of the operation. That which makes is not the attribute of one, and the cause that of another, but of the same, both in the case of the cloak and of the house. For, in as far as one is the cause of anything being produced, in so far is he also the maker of it. Consequently, the cause, and that which makes, and that through which (δι’ ὅ), are the same. Now, if anything is “a cause” and “that which effects,” it is certainly also “that through which.” But if a thing is “that through which,” it does not by any means follow that it is also “the cause.” Many things, for instance, concur in one result, through which the end is reached; but all are not causes. For Medea would not have killed her children, had she not been enraged. Nor would she have been enraged, had she not been jealous. Nor would she have been this, if she had not loved. Nor would she have loved, had not Jason sailed to Colchi. Nor would this have taken place, had the Argo not been built. Nor would this have taken place, had not the timbers been cut from Pelion. For though in all these things there is the case of “that through which,” they are not all “causes” of the murder of the children, but only Medea was the cause. Wherefore, that which does not hinder does not act. Wherefore, that which does not hinder is not a cause, but that which hinders is. For it is in acting and doing something that the cause is conceived.