No concrete test of what is really true has ever been agreed upon. Some make the criterion external to the moment of perception, putting it either in revelation, the _consensus gentium_, the instincts of the heart, or the systematized experience of the race. Others make the perceptive moment its own test,--Descartes, for instance, with his clear and distinct ideas guaranteed by the veracity of God; Reid with his 'common-sense;' and Kant with his forms of synthetic judgment _a priori_. The inconceivability of the opposite; the capacity to be verified by sense; the possession of complete organic unity or self-relation, realized when a thing is its own other,--are standards which, in turn, have been used. The much {16} lauded objective evidence is never triumphantly there, it is a mere aspiration or _Grenzbegriff_, marking the infinitely remote ideal of our thinking life. To claim that certain truths now possess it, is simply to say that when you think them true and they _are_ true, then their evidence is objective, otherwise it is not. But practically one's conviction that the evidence one goes by is of the real objective brand, is only one more subjective opinion added to the lot. For what a contradictory array of opinions have objective evidence and absolute certitude been claimed! The world is rational through and through,--its existence is an ultimate brute fact; there is a personal God,--a personal God is inconceivable; there is an extra-mental physical world immediately known,--the mind can only know its own ideas; a moral imperative exists,--obligation is only the resultant of desires; a permanent spiritual principle is in every one,--there are only shifting states of mind; there is an endless chain of causes,--there is an absolute first cause; an eternal necessity,--a freedom; a purpose,--no purpose; a primal One,--a primal Many; a universal continuity,--an essential discontinuity in things; an infinity,--no infinity. There is this,--there is that; there is indeed nothing which some one has not thought absolutely true, while his neighbor deemed it absolutely false; and not an absolutist among them seems ever to have considered that the trouble may all the time be essential, and that the intellect, even with truth directly in its grasp, may have no infallible signal for knowing whether it be truth or no. When, indeed, one remembers that the most striking practical application to life of the doctrine of objective certitude has been {17} the conscientious labors of the Holy Office of the Inquisition, one feels less tempted than ever to lend the doctrine a respectful ear.