The poet and philosopher Solomon ibn Gabirol, who is lost in enthusiasm in contemplating the powers of the human soul, humbly acknowledges that it was his faith that saved him from fall and ruin. Referring to man’s faculty of acquiring knowledge, he says in his “Royal Crown” ‏כתר מלכות‎: “Who can comprehend Thy wisdom in giving to the soul the faculty of acquiring knowledge, on which her existence depends, knowledge being her foundation? She is permanent and immortal in the same measure as her foundation is well established.” But, reflecting on human weakness, he expresses his feeling of gratitude to the Creator for His guidance in the following words: “Thou hast done yet more for me. Thou hast implanted in my heart a perfect faith, so that I believe in Thee as the true God, and in Thy prophets as true prophets; Thou hast not cast my lot among those that rebel against Thee, or among those who provoke Thy name, despise Thy Law, attack Thy servants, and disbelieve Thy prophets.” Knowledge—philosophy and science—is the very essence, the immortal element of the soul, and yet without the Word of God man would go astray and be lost. The boundaries between faith and reason are more distinctly set forth in the Commentary on Sefer Yetsirah by Dunash ben Tamim (ed. L. Dukes in Shire Shelomoh, i. p. vi. seq.): “All these beings above and below have been created by God, and it is within the province of man to explore and to examine all of them; but he must not pass beyond these boundaries to investigate into the essence of God; ‘for in the city of his refuge shall he dwell,’ and ‘if he goeth out of his place, and the avenger of blood smite him, he hath no remedy.’ Besides, wisdom and science acknowledge that man is unable to comprehend by his own intellect anything that exists outside the sphere of created beings.” R. Bachya, son of Joseph hassephardi, who lived in the eleventh century, treats, in the Introduction to his “Duties of the Heart,” of the three sources of human knowledge—Holy Writ, Tradition, and Reason. Bachya is fully convinced that the knowledge derived from the first two sources is complete and correct. “If you are a man endowed with knowledge and reason, and are able to demonstrate the principles of your belief and your religious practice, which you have been taught by the Sages in the name of the prophets, it is your duty to do so, and to let reason confirm what Tradition teaches. If you abstain from attempting this investigation, you neglect your duty towards your Creator.”