A second response takes Hume's Principle to provide an ontological reduction of numbers to concepts, and relations between concepts. On this view, Hume's Principle is true, but ontological commitments should be read off of the right-hand side. Since the right-hand side, it is supposed, is not ontologically committed to numbers, the left-hand side—being truth-conditionally equivalent—cannot be ontologically committed to numbers either; surface grammar is deceptive here. This response is in line with the standard Quinean approach to paraphrase as a means of eliminating ontological commitment.  But, as noted in §4.2, it is unclear what justifies the asymmetric attitude with respect to commitment. Granted, there is no explicit ontological commitment to numbers by the right-hand side; but once one allows that ontological commitment can be implicit, it is unclear why one cannot say that it is the surface grammar of the right-hand side that is deceptive with respect to ontological commitment.