‘In the beginning God created the heaven and the earth’ (Genesis 1.1). For millions of Jews, Christians and Muslims this has been a fundamental article of belief. Nor is it unknown in the classical Indian traditions. The Upanishads, taken by the orthodox to be ‘heard’, not invented, and to be verbally inerrant, state: ‘He desired: “May I become many, may I procreate” … He created (or emanated) this whole universe’ (Taittiriya Upanishad, 6). The belief that everything in the universe is brought into being by an act of will or desire on the part of one uniquely uncreated being is widespread and fundamental in religion. Historians of religion generally suppose that it is a rather late belief in the Biblical tradition, having developed from an earlier stage at which Jahweh was one tribal deity among others. By the time of the major prophets, however, the notion was firmly established that there is only one God, creator of everything other than himself. Christian theologians always seem to have had a great interest in conceptual problems, and the idea of creation has proved a very fruitful one for generating philosophical puzzles. Those puzzles are still of great theoretical interest, and I shall consider some of them with reference to the work of Augustine and, to a lesser extent Thomas Aquinas. Their views have been so influential that they may fairly be called ‘classical’, in Christian theology.