On the other hand, in natural scienced there are an infinity of conjectures in regard to which certainty can never be expected, because natural appearances are objects that are given to us independently of our concepts, to which, therefore, the key lies not in us and in our pure thinking, but outside us, and for this reason in many cases it is not found; hence no certain account of these a question about the constitution of this something, which cannot be thought through any determinate predicate because it is posited entirely outside the sphere of objects that can be given to us, is entirely nugatory and empty.