{BOOK_2|CHAPTER_2 ^paragraph 85} VIII. Of Belief from a Requirement of Pure Reason.
A want or requirement of pure reason in its speculative use leads only to a hypothesis; that of pure practical reason to a postulate; for in the former case I ascend from the result as high as I please in the series of causes, not in order to give objective reality to the result (e.g., the causal connection of things and changes in the world), but in order thoroughly to satisfy my inquiring reason in respect of it. Thus I see before me order and design in nature, and need not resort to speculation to assure myself of their reality, but to explain them I have to presuppose a Deity as their cause; and then since the inference from an effect to a definite cause is always uncertain and doubtful, especially to a cause so precise and so perfectly defined as we have to conceive in God, hence the highest degree of certainty to which this pre-supposition can be brought is that it is the most rational opinion for us men.