It is entirely contrary to the nature of physico mechanical causes that the whole should be the cause of the possibility of the causality of the parts, for the parts must already be given if we are to grasp the possibility of a whole on the basis of the latter; and further, the particular representation of a whole, a representation that precedes the possibility of the parts, is a mere idea and is called an 'end' if it is regarded as the ground of a causality.