Conscience is commonly said to be educated by *the increase of knowledge* as to the relations of beings and objects, as to the moral laws of the universe, and as to religious verities. This, however, is not true. Knowledge does not necessarily quicken the activity of conscience, or enhance its discriminating power. Conscience often is intense and vivid in the most ignorant, inactive and torpid in persons whose cognitive powers have had the most generous culture. Knowledge, indeed, brings the decisions of conscience into closer and more constant conformity with the absolute right, but it does not render its decisions more certainly in accordance with the relative right, that is, with what the individual, from his point of view, ought to will and do. It has the same effect upon conscience that accurate testimony has upon the clear-minded and uncorrupt judge, whose mind is not made thereby the more active or discriminating, nor his decision brought into closer accordance with the facts as they are presented to him. Knowledge is indeed an indispensable auxiliary to conscience; but this cannot be affirmed exclusively of any specific department of knowledge. It is true of all knowledge; for there is no fact or law in the universe that may not in some contingency become the subject-matter or the occasion for the action of conscience. Nothing could seem more remote from the ordinary field of conscience than the theory of planetary motion; yet it was this that gave Galileo the one grand opportunity of his life for testing the supremacy of conscience,—it may be, the sole occasion on which his conscience uttered itself strongly against his seeming interest, and one on which obedience to conscience would have averted the only cloud that ever rested on his fame. Section II. Sources Of Knowledge. 1. Observation, Experience, And Tradition.