Can concepts ground apriori knowledge? : Peacocke\u27s referential turn and its challenges

The paper is a critical examination of Peacocke\u27s pioneering work on concepts as grounding the possibility of a priori knowledge. It focuses upon his more recent turn to reference and referential domain, and the two enlargements of the purely conceptual bases for apriority, namely appeal to conceptions and to direct referential sensitivity. I argue that the two are needed, but they produce more problem for the strategy as a whole than they solve. I conclude by suggesting that they point to a possible Benacerraf-like dilemma for conceptualists accounts of armchair knowledge: if concepts are akin to representational contents and/or conceptions, they certainly do not metaphysically determine anything. At best, they fallibly guide our inquiry, and get corrected almost by each new important discovery about the nature of their referents. If what is meant by "concept" is a Fregean, objectively correct and metaphysically potent entity, there is little doubt in its power to determine its referent(s), but, there is a huge epistemic problem of how we grasp such Platonic concepts. Peacocke\u27s early metaphysics of concept, which offered beginnings of an answer, is put in jeopardy by the new referential turn, and his valiant attempts to pass between the multiple horns of this dilemma seem to face a lot of difficulties