Faith is the implicit and absolute belief in the truth of the communication made to us and in the trustworthiness of him who makes it to us. The child has faith in its parents that their wishes or commands are for its good; the pupil in his teachers that they impart correct knowledge; we have faith in our friends that they have no intention to deceive us; in the men of science and learning that the results of their researches may be accepted as well established. In all these cases the faith is but imperfect and of a relative and temporary character. Time, investigation, and extended observation and knowledge may either confirm the contents of our faith or may convince us that we have been in error. This is not the case with religious faith. It keeps within the boundaries of its own domain and does not encroach on that of the senses and of reason. Whatever can be known by means of scientific research and thorough investigation we need not accept on faith. Religion—I have, of course, our own religion, the Jewish, in mind—does not only not forbid such examination, but even encourages it. Thus we read in the Book of Proverbs, “A fool believeth every word, but the prudent man looketh well to his going” (xiv. 15). For this purpose God has given us intellectual faculties that we should employ them in our search for truth. At the same time, however, He has set limits to our faculties, and there are things which are beyond these limits, being nistaroth, “things hidden” from our senses, whose existence has been made known to us through the grace of God, by such means as His infinite wisdom determined. We search and investigate, examine and demonstrate, within the sphere of our senses; but all that is beyond their reach belongs to the nistaroth, the knowledge of which can only be imparted to us directly by the Almighty, or indirectly by those to whom they have been communicated by Him. Our belief with regard to these nistaroth may be supported or strengthened by philosophical or dialectical arguments, but can never be proved by mathematical or logical demonstration. The sources from which we derive our knowledge of these nistaroth are Revelation and Tradition. God reveals things otherwise unknown to man to such persons or to such a generation as His wisdom chooses, and from those thus privileged the knowledge spreads to the rest of mankind by means of Tradition. In addition to these two sources there is a third one in ourselves: God implanted in our souls certain ideas common to all of us as essential elements of our inner life, and these ideas form to some extent the basis of our faith. Such is, e.g., the idea of an all-powerful Being, God, who is the source and origin of everything in existence.