The very term “Spirituality” has in recent years acquired negative connotations. In Judaism, it is often associated with an expression of religious fervor devoid of halakhic content or commitment. It conjures up New Age pseudo-religion, unreliable, inconsistent, flaky sentimentality. To borrow a Christian bon mot, “Mysticism,” it is often asserted, “starts in a mist and ends in a schism.” Nevertheless both rationalism and mysticism are equally integral elements in Jewish, indeed all, religious life. It is the relationship between them that I want to explore in this essay.