mind, but a difference in the positiveness and imperiousness with which common sense sets aside opposing hypotheses.
If this is true, the following formula correctly describes all inductive reasoning that seeks to prove causation: "If a certain hypothetical cause exists, the facts would be as I find them. But the facts are as I find them. Therefore, my supposed cause exists." Indeed, from the point of view of the pure intellect, the case is even worse. We assume without any reason that we can justify on purely intellectual grounds that the evidence is all in, that the known relevant facts are all of the relevant facts. How necessary this assumption is, we shall see quite clearly, if we realize how impossible it would be for us to reach any conclusion as to the cause of a violent death, for example, if we admitted in a practical way the possibility of supernatural agencies. If agencies that we know nothing about may exist, and if for reasons and in ways of which we are entirely ignorant they may produce effects similar in kind to those produced by known agencies, how can we ever conclude, on the ground of circumstantial evidence at least, that a known agency is responsible for an event rather than an unknown agency? Nor can it be shown, as Leslie Stephen seeks to do, that the admission of the bare possibility should have nothing to do with our conclusion, because, although possible, the existence of such an agency is in the highest degree improbable. Who knows that? What principle of our nature is it that asserts that, while a supernatural agency may exist and operate in ways and for reasons that we are entirely ignorant of, it is nevertheless in the highest degree improbable? Certainly not the purely intellectual part of us. The intellect gives no criterion for judging of probabilities in such cases. It can only say that, for aught it knows to the contrary, such agencies may exist, and that it knows nothing whatever as to the probability or improbability of their existence. Evidently the practical taking into account of considerations like these, considerations which no amount of reasoning as such justifies us in ignoring, would produce an entire paralysis of our reasoning powers, would make it as impossible for us to emerge from
