By the aid of these views of the nature and relationship of man, we can come to a decision respecting his possession of a criterion of truth. In the earliest moments of his existence he can neither feel nor think, and the universe is to him as though it did not exist. Considering the progress of his sensational powers--his sight, hearing, touch, etc.--these, as his cycle advances to its maximum, become, by nature or by education, more and more perfect; but never, at the best, as the ancient philosophers well knew, are they trustworthy. And so of his intellectual powers. They, too, begin in feebleness and gradually expand. The mind alone is no more to be relied on than the organs of sense alone. If any doubt existed on this point, the study of the phenomena of dreaming is sufficient to remove it, for dreaming manifests to us how wavering and unsteady is the mind in its operations when it is detached from the solid support of the organs of sense. How true is the remark of Philo the Jew, that the mind is like the eye; for, though it may see all other objects, it cannot see itself, and therefore cannot judge of itself. And thus we may conclude that neither are the senses to be trusted alone, nor is the mind to be trusted alone. In the conjoint action of the two, by reason of the mutual checks established, a far higher degree of certainty is attained to, yet even in this, the utmost vouchsafed to the individual, there is not, as both Greeks and Indians ascertained, an absolute sureness. It was the knowledge of this which extorted from them so many melancholy complaints, which threw them into an intellectual despair, and made them, by applying the sad determination to which they had come to the course of their daily life, sink down into indifference and infidelity. But yet there is something more in reserve for man. Let him cast off the clog of individuality, and remember that he has race connexions--connexions which, in this matter of a criterion of truth, indefinitely increase his chances of certainty. If he looks with contempt on the opinions of his childhood, with little consideration on those of his youth, with distrust on those of his manhood, what will he say about the opinions of his race? Do not such considerations teach us that, through all these successive conditions, the criterion of truth is ever advancing in precision and power, and that its maximum is found in the unanimous opinion of the whole human race? [Sidenote: Though no absolute criterion exists, a practical one does.] [Sidenote: The maximum of certainty in the human race.]