“Hear O Israel, the LORD our God, the LORD is one.” Deut. 6:4
This verse is known as the Shema from its first word, which means “hear, listen.” In Judaism, this statement is not just considered a truth, but a mitzvah, a sacred responsibility. In fact, accepting the responsibility of the Shema is so important that it is referred to as “taking on the yoke of the kingdom of heaven.” By doing so, one acknowledges a sole, unique, single God.
Throughout history, this verse has been the cardinal statement of Jewish monotheism. “In the face of polytheism it meant that the Divine is one, not many; in the face of Zoroastrian and Gnostic dualism it meant one, not two; in the face of Christian trinitarianism it meant one, not three; and in the face of atheism, one and not none.” (based on Milton Steinberg’s Basic Judaism)
Prof. Theodore Gaster, a great twentieth century scholar of religion, once told a group of listeners about a man who asked him to teach his son something about Judaism. “Just teach him the unity of God,” he said. The father was probably thinking about monotheism in the sense we have just described. But Gaster realized how complex the subject could be, which is why he raised an exasperated eyebrow as he told the story.
Beyond the affirmation of monotheism, there are other philosophical and mystical implications of God’s unity that resonate strongly throughout Jewish tradition. Maimonides himself is the best known representative of the philosophical tradition. For him this mitzvah affirms “a single source of existence and first cause.” This is the language of Aristotle, whose philosophy was systematically integrated with the theology of the three great monotheistic religions in the Middle Ages, a synthesis best articulated in the works of Averroes (for Islam), Maimonides (for Judaism) and Thomas Aquinas (for Christianity).
That God was “one” in this philosophical tradition meant not only that God was unique, but that God was indivisible, “so that no composition whatever is to be found in him, and no possibility of division.” This obviously rules out God actually having the bodily parts and physical attributes that are mentioned in Scripture, so that when it speaks, e.g., of God’s “mighty hand and outstretched arm” we must understand it as a figure of speech. But it also rules out any change or variation within God, so that to speak of God as “merciful” or “jealous” is just as metaphorical. Thus Maimonides concludes, “If someone believes that He is one, but possesses a certain number of essential attributes, he says in his words that He is one, but believes Him in his thought to be many.” This understanding behooves one to be very circumspect in speaking of God, and makes a dazzled silence more fitting and reverent than a loquacious praise.
The cloak of mystery in which the philosopher wraps the being of God is not so much removed by the mystic as it is thrown over the entire world. Many forms of Jewish mysticism assert that all of reality is one, and all of reality is God. God is not only source, but the substance of all existence. As the Jewish mystic known as the Sfas Emes wrote in a letter to his grandchildren, the “deeper meaning” of the Shema is that “there is no Being other than God. [This is true] even though it seems otherwise to most people. . . . Everything that exists in the world, spiritual and physical, is God Himself. . . . Because of this, every person can become attached to God wherever he is, through the holiness that exists in every single thing, even corporeal things.”
These are the kind of philosophical and mystical implications that hover in the air as we say the Shema. They are not dogmas that Jews are required to believe. But in taking on this mitzvah we find ourselves wrestling with these implications, as Jacob wrestled with God.