5.5422 The correct explanation of the form of the proposition “A judges that p” must show that it is impossible to judge a nonsense [einen Unsinn]. (Russell’s theory does not satisfy this condition.)

Black (p. 301): “Russell’s view was that a judgement has ‘several interrelated objects’ (Principia, vol. 1, p. 43). Judgement requires a relation between the mind and the various constituents of the proposition in question. ‘That is, when we judge (say) “this is red”, what occurs is a relation of three terms, the mind, and “this”, and red’ (ibid.).”