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 actino; and doing something that the cause is conceived.
Besides, what does not hinder is separated from what takes place; but the cause is related to the event. That, therefore, which does not hinder cannot be a cause. Wherefore, then, it is accomplished, because that which can hinder is not present. Causation is then predicated in four ways: The efficient cause, as the statuary; and the material, as the brass; and the form, as the character; and the end, as the honour of the Gymnasiarch.
The relation of the cause sine quâ non is held by the brass in reference to the production of the statue; and likewise it is a [true] cause. For everything without which the effect is incapable of being produced, is of necessity a cause; but a cause not absolutely. For the cause sine quâ non is not Synectic, but Co-operative. And everything that acts produces the effect, in conjunction with the aptitude of that which is acted on. For the cause disposes. But each thing is affected according to its natural constitution; the aptitude being causative, and occupying the place of causes sine quâ non. Accordingly, the cause is inefficacious without the aptitude; and is not a cause, but a co-efficient. For all causation is conceived in action. Now the earth could not make itself, so that it could not be the cause of itself. And it were ridiculous to say that the fire was not the cause of the burning, but the logs,—or the sword of the cutting, but the flesh,—or
