To what class of truths is the word “faith” properly applied? I answer to those which we accept on testimony. It has been asserted that some of the first principles of our rational convictions, such as our belief in the existence of an external world, or in the truth of experience, is an act of faith. This, however, is to introduce a confusion of thought. Such convictions can be only acts of faith as far as we believe in ourselves. Viewing faith as the acceptance of truth on adequate testimony, it follows that all our knowledge of things, whether natural or supernatural, that is not the result of the action of our own minds, but which we accept on the testimony of others, is an act of faith. Our acceptance of them depends on the validity of the testimony that can be adduced for them. The important question for determination is, is the subject on which it is given within the knowledge of the informant? If it respects a fact, has he witnessed it, or received it from others who have? Are his powers of observation good and his judgment sound? Is he worthy of credit? The determination of these and similar points is the proper office of our rational powers, yet the acceptance of the fact is an act of faith. When our reason is satisfied on all these points, faith becomes an act of reason. To assert that the acceptance of supernatural facts belongs to a faculty of our minds which we designate faith, and that our acceptance of others is the result of the action of our reason, is to lay down a distinction entirely of our own creation. In both cases the evidences must form the subject of rational investigation, and they must be accepted or rejected as they approve themselves to our reason.