Let us take another illustration.  If there is one thing that we feel to be as sure as the existence of the external world, it is that there are other minds more or less resembling our own.  The solipsist may try to persuade us that the evidence for such minds is untrustworthy.  We may see no flaw in his argument, but he cannot convince us.  May we ignore him, and refuse to consider the matter at all?

Surely not, if we wish to substitute clear thinking for vague and indefinite opinion.  We should listen with attention, strive to understand all the reasonings laid before us, and then, if they seem to lead to conclusions really not in harmony with our experience, go carefully over the ground and try to discover the flaw in them.  It is only by doing something like this that we can come to see clearly what is meant when we speak of two or more minds and the relation between them.  The solipsist can help us, and we should let him do it.

We should, therefore, be willing to consider seriously all sorts of doctrines which may at first strike us as unreasonable.  I have chosen two which I believe to contain error.  But the man who approaches a doctrine which impresses him as strange has no right to assume at the outset that it contains error.  We have seen again and again how easy it is to misapprehend what is given in experience.  The philosopher may be in the right, and what he says may repel us because we have become accustomed to certain erroneous notions, and they have come to seem self-evident truths.

90.  DO NOT HAVE TOO MUCH RESPECT FOR AUTHORITY.—­But if it is an error to refuse to listen to the philosopher, it is surely no less an error to accord him an authority above what he has a right to demand.  Bear in mind what was said in the last chapter about the difference between the special sciences and philosophy.  There is in the latter field no body of doctrine that we may justly regard as authoritative.  There are “schools” of philosophy, and their adherents fall into the very human error of feeling very sure that they and those who agree with them are right; and the emphasis with which they speak is apt to mislead those who are not well informed.  I shall say a few words about the dangers of the “school.”

If we look about us, we are impressed by the fact that there are “schools” of philosophy, somewhat as there are religious sects and political parties.  An impressive teacher sets the mark of his personality and of his preferences upon those who come under his influence.  They are not at an age to be very critical, and, indeed, they have not as yet the requisite learning to enable them to be critical.  They keep the trend which has been given them early in life, and, when they become teachers, they pass on the type of thought with which they have been inoculated, and the circle widens.  “Schools” may arise, of course, in a different way.  An epoch-making book may sweep men off of their feet