J.D. Collier sees Putnam as arguing that metaphysical realism is false.' He sees the argument as proceeding from the background assumption that metaphysical realism has the consequence that truth is 'radically non-epistemic', so that 'an [epistemically] ideal theory could be radically wrong about the world' [3, p. 413]. But, according to Collier, Putnam argues that 'an ideal theory satisfying all of our methodological and theoretical constraints cannot be false' [3, p. 413]. Collier attempts to defend metaphysical realism against this Putnamian (...) attack by distinguishing 'between our ability to state a theory and our ability to conceive its possibility' [3, p. 413]. I will show that this defence is unsuccessful. (shrink)