Hence the contradictory, and consequently to some extent at least illusory, views of the optimist and the pessimist, "intuitions" which, I have tried to show elsewhere, are connected with deeply rooted habits of feeling, and are antecedent to all reasoned philosophic systems.
If proof were yet wanted that these wide-embracing beliefs may to some extent be illusory, it would be found in the fact that they can be distinctly coloured by a temporary mood or mental tone.

As I have more than once had occasion to remark, a feeling when present tends to colour all the ideas of the time.

And when out of sorts, moody, and discontented, a man is prone to find a large objective cause of his dissatisfaction in a world out of joint and not moving to his mind.
It is evident that all the permanent beliefs touched on in this chapter must constitute powerful predispositions with respect to any particular act of perception, insight, introspection, or recollection.

In other words, these persistent beliefs, so far as individual or personal, are but another name for those fixed habits of mind which, in the case of each one of us, constitute our intellectual bias, and the source of the error known as personal equation.

And it may be added that, just as these erroneous beliefs existing in the shape of fixed prejudices constitute a bias to new error, so they act as powerful resisting forces in relation to new truth and the correction of error.
In comparing these illusions of belief with those of perception and memory, we cannot fail to notice their greater compass or range, in other words, the greater extent of the region of fact misrepresented.
Even if they are less forcible and irresistible than these errors, they clearly make up for this by the area which they cover.
Another thing to be observed with respect to these comprehensive beliefs is that where, as here, so many co-operant conditions are at work, the whole amount of common objective agreement is greatly reduced.