When setting Ira Gershwin’s lyrics for “It Ain’t Necessarily So,” a song in which the literal veracity of the Bible stories is treated with skepticism, George Gershwin turned to Ashkenazi liturgical music for inspiration. The attentive listener will hear the strains of the traditional Blessings of the Torah as the character known as Sportin’ Life tells us that “the things that you’re liable to read in the Bible” may not quite have occurred in the way they are described. This chapter explores the theme of doubt as it appears within Judaism. It explores the origin of the word safek and its range of resonances and meanings, and also explores a theory propounded by Moshe Halbertal concerning the place of doubt in rabbinic, as opposed to sectarian, Judaism. The purpose of the chapter is to suggest that regarding safek as Amalek, a mortal enemy, is not the only way in which doubt is approached in Jewish tradition. Doubt is presented here also as a tool for understanding and a way of seeing.