In order to accurately define understanding, we must separate it from misunderstanding, but not too far, not excessively, otherwise the thing becomes extravagant. The limited formal logic teaches, indeed, that the same thing cannot be affirmed and denied at the same time, affirmation and denial being contradictions. But such a logic is very narrow. Herbs are not weeds. Weeds are the negation of herbs, and still weeds are herbs. An erroneous understanding is a negation of a true understanding, error is not truth, and still it exists in truth. There is no absolute error any more than perceptions are the truth itself. All perceptions are and remain nothing but symbols or reflections of truth. We do not wish to confound error with truth and make a stew of them, but rather understand them both. The mixing is done by the man who opposes them as irreconcilable contradictions. Let us first note the mistake committed in so doing. By so opposing error and truth something is done which is not intended, not known. The intention is to confront the erroneous understanding with truth. For this purpose, error is assumed to be the same as erroneous understanding, which may be admitted; but true understanding and truth are two different things and must be kept separate, if we wish to arrive at clear and unmistakable results. If we formulate the question in this way: How do erroneous and true understanding differ, we are nearer to the desired clarity by two solar distances. We then find that error and understanding do not exclude one another, but are two species of the same genus, two individuals of the same family. Two times two is not alone four; this is only a part of the truth; it is also four times one, or eight times one-half, or one plus three, or sixteen times one-quarter, etc. The man who first observed that the sun circled around the earth once a day, committed a mistake, yet he made a true perception. The apparent circulation of the sun in twenty-four hours around the earth is a substantial part of the understanding which illumines the relation of the motion of the sun and of the earth. No truth is merely simple, but it is at the same time composed of an infinite number of partial truths. The semblance must not be contradictorily separated from truth, in an extravagant sense, but is part of truth, just as all errors contribute toward true understanding. In so far as all perceptions are limited, they are errors, partial truths. True understanding requires above all the backing of the conscious recognition that it is a limited part of the unlimited universe. The cosmic relation of the whole to its parts, of the general to the special, must be considered in order to get a clear conception of the nature of the human understanding.