The epistemological value of simplicity has long been taken as self-evident by natural scientists, and perhaps especially by physical scientists, but as Mario Bunge (1962) reminded us almost half a century ago, there is nothing simple about what that value might be. Indeed, the purported value of simplicity is clearly multiple, as are the very meanings and references of the term. Bunge distinguished two kinds of simplicity: ontological (referring to things, events, processes) and semiotic (referring to concepts, propositions, and theories). When we speak of the epistemological value of simplicity, the reference is clearly to the second meaning, for it is our concepts, propositions, and theories, and not the things, events, and processes they describe, to which epistemic claims attach. And certainly, for the human agents that generate such concepts, propositions, and theories, some of the advantages – having especially to do with the practical value of simplicity -- are self-evident. If we are to be able to work with them, concepts and theories need to be simple enough for us to grasp. Indeed, one might even argue that the very meaning of simple is determined by the capacities of human minds, where those capacities are themselves manifestly shaped by training and, in addition, subject to technological enhancement. Like beauty, simplicity is in this sense in the eye of the beholder.