168	THE  FACTORS OF THE MIND
class : by itself no term can be styled a genus or a species." ^1 In
the same fashion we may say : by itself no factor can be styled
general, group-, or specific ; such designations have reference solely
to the particular set of tests and traits that have been correlated.
This the psychological factorist too often forgets. He speaks of
' the general factor,' as if it formed the ' essence ' (as the logician
would say) of some unique summum genus. In the earlier days of
intellectualistic psychology the factorist's investigations were
concerned exclusively with cognitive tests ; and he was apt to
assume that these covered the whole of the mind. Hence his
general or generic factor, as the context usually reveals, was a factor
which entered into all his cognitive tests, but (though he rarely said
so) into no non-cognitive traits. More recent writers would insist
that the mind possesses conative as well as cognitive aspects.
Consequently, to give a complete description of any individual we
must include his temperamental as well as his intellectual character-
istics. If, then, we start with a set of observed measurements which
include, not only cognitive abilities, but emotional and moral
tendencies as well, Spearman's * general factor ' (g, as he terms it,
commonly identified with general intelligence) will appear to be no
longer a general factor common to all mental traits, but a group-
factor restricted to traits of a comparatively specific kind, namely,
cognitive or intellectual.
Accordingly, so far as the psychological interpretation of
the factors is concerned, the most convenient theory to
adopt will be the most comprehensive : namely, that which
simply states that the mental reactions of our examinees
can always be described in terms of a number of factors of a
greater or a lesser degree of generality. How many kinds of
factors we are to recognize becomes a minor issue. In
principle, as will now be clear, we must regard all factors as
group-factors, and treat the general factor and the specific
factors as merely extreme and limiting cases ; and in that
sense we have to deal with one kind of factor only.
^1 J. Welton, Manual of Logic, I, p. 81.