And then we have to bear in mind that this large amount of error is apt to remain uncorrected. There is not, as in the case of external perception, an easy way of verification, by calling in another sense; a misapprehension, once formed, is apt to remain, and I need hardly say that errors in these matters of mutual comprehension have their palpable practical consequences. All social cohesion and co-operation rest on this comprehension, and are limited by its degree of perfection. Nay, more, all common knowledge itself, in so far as it depends on a mutual communication of impressions, ideas, and beliefs, is limited by the fact of this great liability to error in what at first seems to be one of the most certain kinds of knowledge.
In view of this depressing amount of error, our solace must be found in the reflection that this seemingly perfect instrument of intuitive insight is, in reality, like that of introspection, in process of being fashioned. Mutual comprehension has only become necessary since man entered the social state, and this, to judge by the evolutionist’s measure of time, is not so long ago. A mental structure so complex and delicate requires for its development a proportionate degree of exercise, and it is not reasonable to look yet for perfect precision of action. Nevertheless, we may hope that, with the advance of social development, the faculty is continually gaining in precision and certainty. And, indeed, this hope is already assured to us in the fact that the faculty has begun to criticise itself, to distinguish between an erroneous and a true form of its-operation. In fact, all that has been here said about illusions of insight has involved the assumption that intellectual culture sharpens the power and makes it less liable to err.
ILLUSIONS OF MEMORY.
Thus far we have been dealing with Presentative Illusions, that is to say, with the errors incident to the process of what may roughly be called presentative cognition. We have now to pass to the consideration of Representative Illusion, or that kind of error which attends representative cognition in so far as it is immediate or self-sufficient, and not consciously based on other cognition. Of such immediate representative cognition, memory forms the most conspicuous and most easily recognized variety. Accordingly, I proceed to take up the subject of the Illusions of Memory.