In all things which have a plurality of parts, and which are not a total aggregate but a whole of some sort distinct from the parts, there is some cause.
People lucky enough to live in the vicinity of an industrial hog farm are, with each breath, made keenly aware of the cause of their declining property values.
Everything that depends on the action of nature is by nature as good as it can be, and similarly everything that depends on art or any rational cause, and especially if it depends on the best of all causes.
Nothing in the many processes of Nature, whether she deals with men or with things, comes by chance or accident or is really at the mercy of external causes.