 Such methods must, of course, be applied cautiously—the existence of background conditions makes it difficult to say with certainty that any individual phenomenon is in fact the causally active agent—and results will always be provisional, and open to further correction (Ducheyne 2008). But by carefully varying conditions, Mill holds, we can isolate causes and reveal the laws which govern natural phenomena. We learn first to explain individual events by showing that they are instances of known causal laws, and then “in a similar manner, a law or uniformity in nature is said to be explained, when another law or laws are pointed out, of which that law itself is but a case” (System, VII: 464). By continued application of the Canons of Induction, the most general Laws of Nature can be ascertained—this is the ultimate goal of science. Mill adopts a Humean account of such laws as regularities: “The expression, Laws of Nature, means nothing but the uniformities which exist among natural phenomena” (System, VII: 318). Nevertheless, he thinks that science reveals the deep structure of the world—how things genuinely are.