METAPHYSICAL STATUS OF FACTORS	217
property in either of these senses or in some other remains a
question that cannot be solved by factor-analysis as such.
The function of the nervous system is, in Sherrington's phrase, to facilitate
efficient adaptation by its ' integrative action.' And its capacity for
integration must depend on (i) the number of neurones, (ii) the number of
branches of the neurones, and (iii) the systematic arrangement of those
neurones and their branches. In the cortex of low-grade imbeciles, it is these
three characteristics that are seen to be abnormal; and we may assume that
minor variations of the same kind are to be found in all individuals. Thus,
quite apart from experience, I conceive the neuronic structure of the brain
to be laid down or organized differently in different persons, so that it
' facilitates efficient adaptation ^? in differing degrees. It is also to be noted
that, in the same individual, the nervous tissue, like every other tissue
(e.g. hair), has much the same general structural character throughout.
Consequently, this general structural character of the nervous tissue will
operate as a ^i general factor,' With these facts in mind I went on to argue
that " that mind will, therefore, be most intelligent in which the tendency
to systematization in the portions of the brain as yet unsystematized is great-
est, i.e. where the inborn capacity for complex organization in the nervous
tissue as yet unorganized is most rich : such a capacity can be pictured as
dependent on the general architecture of the central nervous system, and,
being structural, can, like all structures, be conceived as inheritable " ([17],
1909, p. 23 ; cf. [16], p. 169). Thus, like Thomson ([132], p. 54)], I consider
that " persons differ widely in the ^c richness' of their brains," but I lay more
stress on the systematization of* bonds^7 (as he and Thorndike term them) than
upon the mere number of ' bonds.'
Now, if we accept McDougall's view of the attention-process (Mind,
XII, pp. 302 f.), we may regard this integrative, co-ordinating, systematizing
activity of the nervous system as the essential ' physiological factor ' under-
lying attention in its cognitive aspect. Along these lines, it seemed to me
possible to reconcile the views expressed by Wundt and Binet, who held that
intelligence or intellectual power consisted essentially in attention, with the
views of other writers, who had variously described intelligence as power of
adaptation, capacity for learning, capacity for noetic synthesis, or the like.
This suggested reconciliation, however, was merely a corollary to my con-
ception of intelligence, not the primary definition of it. Indeed, instead of
maintaining that * intelligence is merely an effect of attention,' I would
rather say that attention (so far as it is a cognitive and not a conative pheno-
menon) is an effect or symptom of what we call intelligence.
Spearman, it may be noted, would agree to the identification of g with
attention, if attention meant, not ' intensity of conation,' but ^< mental
energy' : McDougall, on the other hand, would prefer to identify * mental
energy' with ^f intensity of conation * and attention with the direction of
energy or conation. Garnett's final way of putting the matter I should
readily accept: " g measures my power to concentrate attention when I wish
to do so ; w is the measure of the influence of my purposes on my use of this
power " (lot. cit., p. 150).