daily life, and shall show that they lead us into difficulty. We are not for the first bound to explain why these assumptions are made. That common sense makes them is enough.
But let the reader remember: The whole value of our argument lies in its perfect generality. However much we dwell on particular classes of errors, we care nothing for the proof that just those errors are inexplicable, but only for the fact that they illustrate how, without some entirely new hypothesis, absolutely all error becomes impossible. This or that class of judgments may be one in which all the judgments are relative, but the total relativity of our thought implies an incomprehensible and contradictory state of things. Any hypothesis about error that makes total relativity the only admissible view, must therefore give place to some new hypothesis. And our illustrations in the following are intended to show that just what constitutes the difficulty in respect of these illustrations, makes the existence of any error inexplicable without some new hypothesis.
V.
The class of errors that we shall first take seems, to common sense, common enough. It is the class known as errors about our neighbor’s states of mind. Let us then, for argument’s sake, assume without proof that our neighbors do exist. For we are not here concerned to answer Solipsism, but merely to exemplify the difficulties about the nature of error. If our neighbors did not exist, then the nature of
