The guide

I consider the following opinion as most correct according to the teaching of the Bible and the results of philosophy, namely that the universe does not exist for man's sake, but that each being insists for its own sake, and not because of some other thing. Thus we believe in Creation, and yet need not inquire what purpose is served by each species of existing things, because we assume that G-d created all parts of the universe by His will; some for their own sake, and some for the sake of other beings (III:13) . . . Consider how vast are the dimensions and how great the number of these corporeal beings. If the whole of the earth would not constitute even the smallest part of the sphere of the fixed stars, what is the relation of the human species to all these created things, and how can any of us imagine that they exist for his sake and that they are instruments for his benefit? (III:14)

Moses Maimonides, Guide for the Perplexed