 In Lucretius’s The Nature of the Universe – which is the greatest classical statement of a system of atheism – it is argued that it is impossible that matter was created and that it must, therefore, be eternal and uncreated. The basis of this argument is the general causal principle: “Nothing can come from nothing” [Ex nihilo, nihil fit.] In the late 17th and early 18th centuries this principle was turned against the Epicurean atheism of thinkers such as Lucretius and his modern counterparts. More specifically, the principle “Nothing can come from nothing” was taken to ground two derived principles of causal reasoning. The first is the causal maxim: Whatever exists must have a cause or ground for its existence. The second principle is that of causal adequacy or the order of causes: No cause can produce or give rise to perfections or excellences that it does not itself possess. These two (derived) causal principles were used by religious philosophers like Cudworth, Locke and Clarke as the philosophical foundation for their own versions of the cosmological argument. It fell to Hume to argue that the causal foundations of this argument were too weak to support the philosophical weight placed upon them.