Our belief in the existence of other minds is not reached by inference; and our belief in the existence of material objects is not reached by inference. Nevertheless, each of these beliefs can be rendered probable by certain inverse or analogical arguments, provided we admit that they have a finite antecedent probability. But the two beliefs are not logically independent of each other. For some, at any rate, of the arguments which support the belief in matter depend on our accepting the statements of other people about their perceptions; and the acceptance of such statements presupposes our belief in other minds. Again, arguments by analogy to support our belief in other minds presuppose either
a. that the feelings which we feel and the sensa which we sense are appearances to us of material objects, or
b. that some sensa are capable of being sensed by more than one mind.
Since the second condition is doubtful, whilst the first is sufficient even if the second be false, it follows that arguments by analogy in support of our belief in other minds are stronger if we believe that sensa are appearances of matter than if we do not.
[C. D. Broad, Mind and Its Place in Nature, Chapter 7.]
This question of the relation between our belief in the material world and our belief in other minds is an interesting one; I'm reminded of Arnauld, who thinks that it is more certain that there are other minds than that there is a material world, and so argues for the existence of the material world by arguing for it as a sort of intersubjective medium.
