Reliabilism about knowledge states that a belief-forming process generates knowledge only if its likelihood of generating true belief exceeds 50 percent. Despite the prominence of reliabilism today, there are very few if any explicit arguments for reliabilism in the literature. In this essay, I address this lacuna by formulating a new independent argument for reliabilism. As I explain, reliabilism can be derived from certain key knowledge-closure principles. Furthermore, I show how this argument can withstand John Turri’s two recent objections to (...) reliabilism: the argument from explanatory inference and the argument from achievements. (shrink)