Third, even if the existence of a highest intelligence were proved, we would, to be sure, be able to make that which is purposive in the arrangement and order of the world comprehensible in general, but would by no means be authorized to derive from it any particular arrangement and order, or boldly to infer one where it is not perceived, for it is a necessary rule of the speculative use of reason not to bypass natural causes and aban don that about which we could be instructed by experience in order to derive something that we know from something that entirely surpasses all our knowledge.