Though it is less often spoken of, we may remark that the measure of continuous quantity passed through the same concrete-abstract phase; and here it appeared at a somewhat early stage, owing to practical and social wants. Hence we find at the outset, the foot, the finger, the thumb (inch = Fr. _pouce_), the palestra (four fingers’ length), span, cubit (arm’s reach = _coudée_), fathom, etc., the stadium (distance a good runner could cover without stopping).[76] The concrete character of all these measures is obvious. Again, there are survivals in certain current locutions, such as a day’s journey. More than this; they have a _human_ character, their standard and starting-point being, at least at the outset, certain parts of the body, or a determined sum of muscular movements. Little by little they lost their original significance, progressing through centuries towards our metrical system the type of a scientific, deliberate, rationally abstract system, as far as possible liberated from anthropomorphism. The reader will probably obtain a more definite idea of the nature of these lower forms by recapitulating the examples cited, than from any long dissertation. Is their intellectual level very superior to that of the generic image? This question is doubtful. At times the only distinction between them is the presence of the word: at the present stage it makes but a poor figure,—yet with all its modesty, it augurs a new world wherein it is to be of prime importance. II. We now pass to a study of transition. In ascending from the lower to the _higher_ forms of abstraction, we traverse the intermediate region between the states directly superposed upon generic images, and the higher concepts. In fact, we shall to some extent have to penetrate into this extreme region, before the close of the chapter. At the risk of repetition, we must first indicate the characteristics by which the general notions we are at present concerned with are distinguished from the abstractions above and below them. To recapitulate briefly: In the concrete-abstract phase (which we are leaving) the general notion—so-called—is constituted by concrete elements, _plus_ words, whose substitutory office is weak or null. In the abstract phase (upon which we are entering) the concept is constituted by an evoked or evocable image, which may exhibit every degree from clear representation to the pure schema, _plus_ the word that now becomes the principal element. In the phase of higher abstractions (to be studied later), no sensory representation arises, or should any such appear, reflexion would find in it only a dubious support, often an obstacle: the word meantime has acquired absolute supremacy in consciousness. Taken as a whole, psychological development exhibits a complex phenomenon, a binary compound, in which one element is always increasing, the other as steadily decreasing. Words pass from nonentity to autocracy; the concrete from supremacy to nonentity.