This difference between the purely ideal and the real order did not escape the scholastics. They were accustomed to say that there was no science of contingent and particular, but only of necessary and universal things. In the place of _contingent_ substitute _reality_, since all finite reality is contingent; and instead of _universal_ put _ideal_, since the purely ideal is all universal; and you will have the same doctrine enunciated in distinct words. It is not easy to show exactly how far modern philosophers have availed themselves of the scholastic doctrine, in so far as the distinction between pure and empirical cognitions is concerned; but it is certain that some very clear passages upon these questions are to be found in the works of the scholastics. It would not be strange if some moderns, particularly Germans, whose laboriousness is proverbial, especially in matters of erudition, had read them.(27) CHAPTER XXXII. THE CRITERION OF COMMON SENSE. 313. _Common sense_ is an exceedingly vague expression. It should, like all expressions which contain many and different ideas, be considered under two aspects: that of its etymological, and that of its real value. These two values are not always the same; they are sometimes greatly discrepant; but even in their discrepancy, they usually preserve intimate relations. We must not, in order duly to appreciate the meaning of such expressions, confine ourselves to their philosophical, and contemn their vulgar meaning. In the latter there is often a profound philosophy; for, in such cases, the vulgar sense is a kind of precious sediment left by the flow of reason upon the word during many ages. It thus happens that in measure, as the vulgar sense is understood and analyzed, the philosophical question is determined, and the most intricate questions solved with the greatest facility. 314. It is remarkable, that besides the corporal senses there should be another, called _common sense_. _Sense_: This word excludes reflection, all reasoning, all combination; nothing of this kind enters into the meaning of the word _to sense_. When we sense, the mind is rather passive than active; it does nothing of itself; it does not give, it receives; it suffers, but does not perform, an action. This analysis leads us to a very important result, and this is, the separation from common sense of all that upon which the mind exercises its activity; and the determination of one character of this criterion, which is, with respect to common sense; the understanding has nothing to do but submit itself to a law _perceived_, to an instinctive and unavoidable necessity. 315. _Common_: This word excludes all individuality, and shows the object of common sense to be general to all men.