85. As has already been suggested (37), these six kinds of interest arise from two sources to which historical and nature studies respectively correspond. With this the facts observed in classical high schools (_Gymnasia_) coincide: pupils usually lean toward one side or the other. It would be a serious blunder, however, to affirm, on this account, an antithesis between the historical and the natural science interest; or, worse still, to speak of a philological and a mathematical interest instead--as is, indeed, not infrequently done. Such confusion in ideas should not continue; it would lead to utterly erroneous views of the whole management of instruction. The easiest means to counteract the evil is a consideration of the multitude of one-sided tendencies that occur even within the six kinds of interest; we shall be able, at all events, to bring out still more clearly the manifold phases of interest that must be taken into account. For the possible cases of one-sidedness are differentiated far more minutely than could be shown by the discrimination of only six kinds of interest. “Is the ideal education classical or scientific?” This question, which is still debated, really means, shall we cultivate chiefly the _social_ or the _knowledge_ interests. The historical, or culture, studies belong preëminently on the one side, the natural sciences most largely on the other. Herbert Spencer in 1860 made a special plea for science studies in his monograph, “Education,” claiming that such studies are of chief worth both for knowledge and training. At that time classical, or culture, studies had possession of almost every institution for higher education, so that Spencer’s special plea was justified. At present, however, science, which has developed its own methods of instruction, holds an equal place with social studies in the colleges and universities. When we are asked which half of human interests we will choose, the knowledge or the social, our reply can only be: We will abandon neither, but choose both. Both are essential to human happiness; both are necessary for social and material advance. 86. Empirical interest becomes one-sided in its way when it seizes upon one kind of objects of experience to the neglect of the rest. When, for instance, a person wants to be a botanist exclusively, a mineralogist, a zoölogist; or when he likes languages only, perhaps only the ancient or only the modern, or of all these only one; or when as a traveller he wishes to see, like many so-called tourists, only the countries that everybody talks about, in order to have seen them too; or when, as a collector of curiosities, he confines himself to one or the other fancy; or when, in the capacity of historian, he cares only about the information bearing on one country, or one period, etc.