Here, then, we seem to have the key to the apparently paradoxical fact that a man, with all his superior means of studying his own feelings, commonly esteems himself, in certain respects at least, less accurately than a good external observer would be capable of doing.  In forming an opinion of ourselves we are exposed to the full force of a powerful impulse of feeling.  This impulse, acting as a bias, enters more or less distinctly into our single acts of introspection, into our attempts to recall our past doings, into our insights into the meaning of others’ words and actions as related to ourselves (forming the natural disposition to enjoy flattery), and finally into our wild dreams as to our future achievements.  It is thus the principal root of that gigantic illusion of self-conceit, which has long been recognized by practical sense as one of the greatest obstacles to social action; and by art as one of the most ludicrous manifestations of human weakness.

If there are all these openings for error in the beliefs we go on entertaining respecting individual things, including ourselves, there must be a yet larger number of such openings in those still more compound beliefs which we habitually hold respecting collections or classes of things.  A single illusion of perception or of memory may suffice to give rise to a wholly illusory belief in a class of objects, for example, ghosts.  The superstitious beliefs of mankind abundantly illustrate this complexity of the sources of error.  And in the case of our every-day beliefs respecting real classes of objects, these sources contribute a considerable quota of error.  We may again see this by examining our ordinary beliefs respecting our fellow-men.

A moment’s consideration will show that our prevailing views respecting any section of mankind, say our fellow-countrymen, or mankind at large, correspond at best to a very loose process of reasoning.  The accidents of our personal experience and opportunities of observation, the traditions which coloured our first ideas, the influence of our dominant feelings in selecting for attention and retention certain aspects of the complex object, and in idealizing this object,—­these sources of passive and active illusion, must, to say the least, have had as much to do with our present solidified and seemingly “intuitive” knowledge as anything that can be called the exercise of individual judgment and reasoning power.

The force of this observation and the proof that such widely generalized beliefs are in part illusory, is seen in the fact that men of unlike experience and unlike temperament form such utterly dissimilar views of the same object.  Thus, as Mr. Spencer has shown,[144] in looking at things national there may be not only a powerful patriotic bias at work in the case of the vulgar Philistine, but also a distinctly anti-patriotic bias in the case of the over-fastidious seeker after culture.  And I need hardly add that the different estimates of mankind held with equal assurance by the cynic, the misanthropist, and the philanthropic vindicator of his species, illustrate a like diversity of the psychological conditions of belief.