I shall use 'epistemic warrant' and 'epistemic justification' interchangeably for a normative property that provides a good route to true belief and knowledge. 1 Here are two facts:FACT ONE: Beliefs based on taking perceptual experiences at face value are defeasibly epistemically warranted. FACT TWO: Defeasibly taking perceptual experience at face value is a reliable route to true belief.Epistemologists disagree over their relationship.Reliabilists believe the second helps explain the first. And by "explain" the reliabilist sets out to really, genuinely explain, to "state conditions that clarifies the underlying source of justificational status,. . . conditions [that are] appropriately deep or revelatory," not simply conditions that state 1 There are at least four senses of 'justification' in epistemology. (1) In its broadest use in English, 'justification' involves meeting a norm or standard. Applied to epistemology, for any norm or standard relevant to the evaluation of beliefs from the point of view of promoting, acquiring, or sustaining true belief and knowledge, a belief or believer or activity may be 'justified' relative to that standard. (2) Focusing on the evaluation of belief for knowledge, 'epistemic justification' is interchangeable with 'warrant'-that normative property of belief that provides a good route to truth and knowledge.(3) When a warrant for knowledge involves operative reasons supporting the belief, those reasons are a justification for the belief. These reasons may be entirely first-order, object-directed. (4) When a warrant for knowledge involves critical reasons-warranted beliefs about one's mental states as providing warrants for belief, those critical reasons provide a critical justification. Critical justifications ground the activity of justifying a belief, to giving reasons in favor of the truth or the belief-worthiness of the belief. Many epistemologists use 'justification' in this sense. Justifications in the third and fourth senses are not (always) required for warrant. Perceptual beliefs, the beliefs of pre-linguistic children, and the (possible) beliefs of higher non-human animals are frequently warranted and knowledge without justifications in the sense of warrants involving reasons or critical reasons (