The question in the title is similar to other important unsettled questions prompted by attempted mathematical characterizations of pretheoretical notions, by coextensionality "theses" about them. 1 Church and Turing's thesis that a function is computable iff it is recursive 2 gives rise to the question "are there computable functions that are not recursive?". The thesis, especially associated with Stephen Cook, that a natural problem has a feasible algorithm iff it has a polynomial-time algorithm 3 gives rise to the question "are there natural problems having a feasible algorithm that do not have a polynomial-time algorithm?". 4 But there are remarkable dissimilarities too. A central one is that the notion of "model-theoretic logical truth" is a notion relative to (at least) a choice of a set of formalized languages, of a set of logical constants, of a notion of model, and of a notion of truth in a model, while the notions of recursiveness and of a polynomial-time algorithm are * Parts of this paper were presented in workshops at the University of California at Irvine (2002), the Universidade Nova de Lisboa (2003), the University of Melbourne (2004), and the Universidad de Santiago de Compostela (2006), and as lectures at the Universidad Nacional Autónoma de México (2006) and the Universidade Federal do Rio de Janeiro (2006). I thank the audiences at these events for very helpful comments and criticism. Special thanks to Rodrigo Bacellar, Bill Hanson, Øystein Linnebo, Gila Sher and two anonymous readers. 1 Here by "pretheoretical" of course I don't mean "previous to any theoretical activity"; in this sense there could hardly be pretheoretical notions of computability, of a feasible algorithm, or of logical truth. What I mean is "previous to the theoretical activity of mathematical characterization".