 This line of reasoning, remarkably similar to what Kant had argued in the Fourth Antinomy in the first edition of the Critique of Pure Reason but rejected as an inadequate refutation of idealism in the second edition, was picked up in an abbreviated form by Russell ten years later in the chapter on idealism in his The Problems of Philosophy, while the attack on Bradley, although foreshadowed in Russell’s Problems, is spelled out rather lengthily (and a bit nastily) by Moore in “The Conception of Reality” from 1917–18. Their main objection against the two idealistic arguments seems to be that they rely on unjustly presupposing that the mental act of relating to an object (perceiving, thinking, knowing, experiencing) is a necessary condition for the existence of this object. The fallacy involved here consists in failing to make “the distinction between act and object in our apprehending of things”, as Russell (1912 [1974: 42]) puts it, or, in Moore’s terminology of The Refutation, in wrongfully identifying the content of “consciousness” with its object (1912 [1974: 19 ff.]). As soon as this identification is given up and that distinction is made it is at least an open question whether things exist independently of the mind, and idealism insofar it neglects this distinction and holds fast to that identification is refuted because based on an invalid argument.