This paper proposes a general account of the epistemological significance of inference. This account rests on the assumption that the concept of a “justified” belief or inference is a normative concept. It also rests on a conception of belief that distinguishes both (a) between conditional and unconditional beliefs and (b) between enduring belief states and mental events of forming or reaffirming a belief, and interprets all of these different kinds of belief as coming in degrees. Conceptions of “rational coherence” and “competent inference” are then formulated, in terms of the undefeated instances of certain rules of inference. It is proposed that (non-accidental) rational coherence is a necessary and sufficient condition of justified enduring belief states, while competent inference always results in a justified mental event of some kind. This proposal turns out to tell against the view that there are any non-trivial cases of “warrant transmission failure”. Finally, it is explained how these proposals can answer the objections that philosophers have raised against the idea that justified belief is “closed” under competent inference.