It is plain, I think, that a man may believe two true propositions, of which the one would not be true, unless the other were true too, without, in any sense whatever, having arrived at his belief in the one from his belief in the other; and it is plain, at all events, that the question whether his belief in the one did arise from his belief in the other, is a different question from the question whether the truth of the one belief follows from the truth of the other.