A contrast is drawn between two types of externalism, one based on ideas of Wittgenstein, the other on arguments from Putnam. Gregory McCulloch’s attempt to combine the two types is then examined and criticized. Putnamian externalism is ambiguous. It can be interpreted either as the empirical claim that we give priority to scientific as opposed to other forms of discourse, or as a metaphysical claim that our language attempts to conform to the structure of the world ‘in itself’. But the first claim is simply false, and the second involves a form of metaphysical realism that a Wittgensteinian must reject as unintelligible. McCulloch’s attempted synthesis of the two types is therefore either incoherent, or else simply adds an empirical falsehood to Wittgenstein’s conceptual point. It is also noted that Putnam himself has progressively retreated from his original claims, and now appears to be a Wittgensteinian, but not a ‘Putnamian’, externalist.