The rabbis penetrated deeply into the spirit of Scripture, at the same time that they adhered strictly to its letter. While they clung tenaciously to the ritual holiness of the priestly codes, they recognized the ideal of holiness which is so sharply opposed in every act and thought to the demoralizing cults of heathenism.(268) 7. Accordingly, holiness is not the metaphysical concept which Jehuda ha Levi considers it,(269) but the principle and source of all ethics, the spirit of absolute morality, lending purpose and value to the whole of life. As long as men do good or shun evil through fear of punishment or hope for reward, whether in this life or the hereafter, so long will ideal morality remain unattained, and man cannot claim to stand upon the ground of divine holiness. The holy God must penetrate and control all of life—such is the essence of Judaism. The true aim of human existence is not salvation of the soul,—a desire which is never quite free from selfishness,—but holiness emulating God, striving to do good for the sake of the good without regard to recompense, and to shun evil because it is evil, aside from all consequences.(270) 8. The fact is that holiness is a religious term, based upon divine revelation, not a philosophical one resting upon speculative reasoning. It is a postulate of our moral nature that all life is governed by a holy Will to which we must submit willingly, and which makes for the good. How volition and compulsion are with God one and the same, how the good exists in God without the bad, or holiness and moral purpose without unholy or immoral elements, how God can be exactly opposite to all we know of man,—this is a question which philosophy is unable to answer. In fact, holiness is best defined negatively, as the “negation of all that man from his own experience knows to be unholy.” These words of the Danish philosopher Rauwenhoff are made still clearer by the following observations: “The strength in the idea of holiness lies exactly in its negative character. There is no comparison of higher or lesser degree possible between man’s imperfections and God’s perfect goodness. Instead, there is an absolute contrast between mankind which, even in its noblest types, must wrestle with the power of evil, and God, in whom nothing can be imagined which would even suggest the possibility of any moral shortcoming or imperfection.”(271) As the prophet says, “Thou art too pure of eyes to look complacently upon evil,”(272) and according to the Psalmist, “Who shall ascend into the mountain of the Lord, and who shall stand in His holy place? He that hath clean hands and a pure heart.”(273)