 Ordinary beliefs and interpretations, including perceptual beliefs, are, for Lewis, typically the product of habit or association in which we are guided by the elements of the given in the epistemological present but rarely if ever attend to them. Nonetheless, the justification of these beliefs as rationally credible requires that there be an inferential or logical relationship of a belief or a statement of it to grounds or reasons in experience that constitute evidence, largely inductive, for it (Lewis 1946, 315, Lewis 1952a, reprinted in Lewis 1970, 326). For Lewis, “the critical question for the validity of empirical knowledge is not whether grounds sufficient for the justification of the belief are actually contained in the explicit psychological state of the believer, but whether the knower’s situation in empirical belief is such that sufficient grounds could be elicited upon inquiry, or whether it is such that this is even theoretically impossible” (Lewis 1946, 330). Restricting the term “knowledge” to cases where grounds are explicit would “be so rigoristic as to exclude most, if not all, of our attempted cognitions and would obscure the important distinction of practically valuable knowledge from ‘ignorance’ and from ‘error’” (Lewis 1946, 330), just as restricting the term to what we are certain of would. Nor should we think that the act of reflecting on and eliciting what in the epistemological present justifies our beliefs loses or takes us beyond the epistemological present (Lewis 1946, 330–2), and thus is an impossible ideal. 