6. CLASSIFICATION—COMPARED WITH DIVISION.
Classification is the process of grouping notions according to their resemblances or connections.
So far as results are concerned there is no differencebetween logical division and classification. Both processes may give us the same orderly scheme of heads and subheads. The difference lies in the process itself. Division is deductive in nature as it proceeds from the more general genus to the less general species. While classification is inductive as it groups the less general species under the more general genus. Division differentiates unity into multiplicity, while classification reduces multiplicity to unity. It follows that the one is the inverse of the other. The difference in the mode of procedure may be illustrated by using the common classification or division of triangles. For example:
Without any knowledge of the kinds of triangles the student discovers by examining the various shapes of many triangles that there is a group in which none of the sides are equal. For the lack of a better name he terms these non-equilateral (scalene). Further observation discloses another group in which two of the sides are equal. These he names bi-equilateral (isosceles). Finally a third group is designated as tri-equilateral (equilateral). This process is classification. Division would consist in separating the genus triangle into the three kinds—scalene, isosceles, equilateral.