committed itself to a premature classification that allowed of no revision, and saddled the inheritors of its language with a science that they no longer quite believed in nor had the strength to overthrow.  Dogma, rigidly prescribed by tradition, stiffens into formalism.  Linguistic categories make up a system of surviving dogma—­dogma of the unconscious.  They are often but half real as concepts; their life tends ever to languish away into form for form’s sake.

[Footnote 63:  Hence, “the square root of 4 is 2,” precisely as “my uncle is here now.”  There are many “primitive” languages that are more philosophical and distinguish between a true “present” and a “customary” or “general” tense.]

There is still a third cause for the rise of this non-significant form, or rather of non-significant differences of form.  This is the mechanical operation of phonetic processes, which may bring about formal distinctions that have not and never had a corresponding functional distinction.  Much of the irregularity and general formal complexity of our declensional and conjugational systems is due to this process.  The plural of hat is hats, the plural of self is selves.  In the former case we have a true _-s_ symbolizing plurality, in the latter a z-sound coupled with a change in the radical element of the word of f to v.  Here we have not a falling together of forms that originally stood for fairly distinct concepts—­as we saw was presumably the case with such parallel forms as drove and worked—­but a merely mechanical manifolding of the same formal element without a corresponding growth of a new concept.  This type of form development, therefore, while of the greatest interest for the general history of language, does not directly concern us now in our effort to understand the nature of grammatical concepts and their tendency to degenerate into purely formal counters.

We may now conveniently revise our first classification of concepts as expressed in language and suggest the following scheme: 

  I. Basic (Concrete) Concepts (such as objects, actions, qualities): 
    normally expressed by independent words or radical elements; involve
    no relation as such[64]

 II. Derivational Concepts (less concrete, as a rule, than I, more so
    than III):  normally expressed by affixing non-radical elements to
    radical elements or by inner modification of these; differ from type
    I in defining ideas that are irrelevant to the proposition as a
    whole but that give a radical element a particular increment of
    significance and that are thus inherently related in a specific way
    to concepts of type I[65]