Page:Popular Science Monthly Volume 11.djvu/408

392 these two things. Of such shocks is made up one-half of what we term knowledge.

Whenever there is a difference it should be felt by us; and so wherever there is an agreement it should be felt. To overlook either the one or the other is stupidity of mind. Our education marches in both lines; and, in so far as we are helped by the schoolmaster, we should be helped in both. The artifices that promote discrimination, and the influences that thwart it, have been already considered; and many of the observations apply also to agreement. In the identifying of like in the midst of unlike, there are cases that are easy; and there are cases that the unassisted mind fails to perceive.

1. We must repeat, with reference to the delicate perception of Agreements, the antithesis of the intellectual and the emotional outgoings. It is in the stillness of the emotions that the higher intellectual exercises are possible. This circumstance should operate as a warning against the too frequent recourse to pains and penalties, as well as against pleasurable and other excitement. But a more specific application remains.

We may at once face the problem of general knowledge. The most troublesome half of the education of the intellect is the getting possession of generalities. A general fact, notion, or truth, is a fact recurring under various circumstances or accompaniments: "heat" is the name for such a generality; there are many individual facts greatly differing among themselves, but all agreeing in the impression called heat—the sun, a fire, a lamp, a living animal. The intellect discerns, or is struck with, the agreement, notwithstanding the differences; and in this discernment arrives at a general idea.

Now the grand stumbling-block in the way of the generalizing impetus is the presence of the individual differences. These may be small and insignificant; in comparing fires with one another, the agreement is striking, while the differences between one fire and another, in size, or intensity, or fuel, do not divert the attention from their agreement. But the discerning of sameness in the sun's ray and in a fermenting dung-heap is thwarted by the extraordinary disparity; and this conflict between the sameness and the difference operates widely and retards the discovery of the most important truths.

2. The device of juxtaposition applies to the expounding of agreement, no less than of difference. We can arrange the several agreeing facts in such a way that the agreement is more easily seen. The effect is gained partly by closeness, as in the case of differences, and partly by a symmetrical contact, as when we compare the two hands by placing them finger to finger, and thumb to thumb. Such symmetrical comparisons bring to view, in the same act, agreement and difference. The method reaches far and wide, and is one of the most powerful artificial aids to the imparting knowledge.