The selection from Russell comes from near the end of a long book on the theory of knowledge, where it appears in a part titled "Postulates of Scientific Inference." As the first sentence of the selection suggests, Russell is interested in the example of our knowledge of other minds mainly as an illustration of a further postulate, which he states at the end of the selection. But, along the way, he gives a clear presentation of the most common for the existence of other minds that is usually referred to as the "argument by analogy."

Malcolm mentions this form of the argument but also a few variations on it, and one thing you might do is to ask yourself which seems to be the strongest. Malcolm was a student of Wittgenstein's, and his criticisms of these arguments are drawn largely from things Wittgenstein says. The idea of a "criterion" he uses is also influenced by Wittgenstein, who employs at times a distinction between "criteria" and "symptoms." You can think here of how the symptoms of a disease might be distinguished from criteria used to define its presence. Although Wittgenstein did not think the meanings of most words we use could be captured by definitions, he has sometimes been understood to hold that the meaning of terms used to report observations are associated with certain defining criteria. (Others would deny that Wittgenstein intended to offer any general account of the nature of meaning at all.) Malcolm uses these ideas to criticize not only various solutions to the problem of other minds but also the problem itself. So one thing to ask yourself is whether you think it is a pseudo-problem.

Malcolm's paper was a lecture at a philosophy conference and was followed at that conference by a lecture by Herbert Feigl, who is one of the identity theorists we read earlier in the course. In that lecture (which is in the same issue of The Journal of Philosophy), he presented an identity theorist's response to the problem of other minds. So you might think what not only Feigl but people like Place or Smart might say about the problem of other minds. Feigl also mentions the article by Sellars from which you read a selection, and Sellars was thinking of both the problem of other minds and Wittgenstein's views when he offered the account of thought that you read.