Of the principle of the teleological judging of nature in general as a system of purposes

We have already said above that the external purposiveness of natural things affords no sufficient warrant for using them as purposes of nature in order to explain their presence, and for regarding their contingently purposive effects as the grounds of their presence according to the principle of final causes.

Thus we cannot take for natural purposes, rivers because they promote intercourse among inland peoples, mountains because they contain the sources of the rivers and for their maintenance in rainless seasons have a store of snow, or the slope of the land which carries away the water and leaves the country dry; because although this shape of the earth’s