tion may be met with the rejoinder that our knowledge is as yet too incomplete to make the prediction successful. It may be asked, Do you really mean to affirm that if we knew the cosmos through and through we should not then know its possibilities and its eventualities? Does the fact that we must wait for events to happen before we can discover their causes give us the slightest warrant for supposing that those causes, even before we discovered their effects, were not competent to produce them, would not, in fact, produce them? And if so, is it not simply nonsense to affirm that we could not have predicted what those causes would produce if we had really known what those causes were? Is not such an affirmation one more instance of the stupid failure to distinguish between the ratio cognoscendi of things and their ratio essendi or fiendi?
Questions like these may impose upon the mind, but they do not clarify it. To be sure, if we knew the full competency of things and how and when that competency would be exercised, there would be nothing left to discover. This we do not know and we may confidently say that we never shall know it. That we shall not does not indicate a defect in our faculties, some limitation which we vainly try to leap over. It indicates rather that our knowing is itself an event, one of nature's happenings, an item of history. The ratio fiendi and the ratio cognoscendi look strange, do they not, when applied to the fact of knowledge itself; if they force us to affirm that if we knew—let us say, the primeval condition of all things—we should then be in a position to state what our knowledge of it would eventually be and whether that knowledge would be correct or not. We owe idealism a profound debt for that piece of dialectic, even if we charge idealism with the failure to profit by it. It, too, imposes upon the mind even if it does not clarify it. What intelligible meaning can be attached to the statement that if I knew the antecedents of my present knowledge, I should then be able to tell from those antecedents what my present knowledge is? The antecedents of my present knowledge are not my knowledge, and the antecedents of the hen are not the hen. And I have not been able to discover any wisdom or profit in putting my present knowledge
