1897.] The Biologie Origin of Mental Variety: 13 
of most “ good science” to avoid.“ speculation ” on these topics. 
Yet it is the loosest and most reckless kind of wholesale specu- 
lation, to build up the whole of modern Psysiology and Biology 
on the theory that all but a certain fraction of neural activities 
are unconscious, while really so little is known of the whole 
subject. Already, in my last lecture,*? I have pointed out the 
evils resulting from doing this in several concrete problems of 
Physiology. We have now to consider these results in a larger 
field. The truth is that the right to dub all subcortical neural 
activics “unconscious,” though but little contested since the 
death of Pfluger, still rests on little else than ill-founded prej- 
udice.* And to dub them so on insufficient grounds isto run 
3 A lecture on “ Psychology and Physiology,” next preceeding the present one 
in the course mentioned in note on p. 963. 
+ A crucial departing point for practical errors in all assumption of ‘‘ uncon- 
scious” processes must obviously lie in the criterion applied for deciding whether 
_ consciousness is present or not. The tests heretofore applied are always either the 
“ purposeness ” of the activity in question, or our “immediate cognizance” of it, 
in case it is an activity within our body. It is evidence of the surprising ease with 
which Science is led astray in these matters, that both of these tests prove the 
shallowest sort of fallacies when properly examined. If by ‘‘purposeness” be 
meant psychologic purposing, or conceiving of the end to be accomplished, by the 
creature performing the act, and immediately initiatory to its performance, then 
plainly this is preposterous. Notoriously not all “ motor ideas” are of this sort. 
If “ability” to preconceive the end be meant, then this is more absurd ; since it 
makes the “ability ” of consciousness the test, where the presence of consciousness 
is to be tested. And again if mere conduciveness to some purpose is meant, 
why then, every iron locomotive and nearly scales else in nature must, by 
this test, be a “conscious ” machine. It is remarkable that such psychologists 
as Romanes, Profs. Wm. James, Lloyd Moric and Edward D. Cope should 
stumble into such a visible pitfall in matters of such grave importance. 
Regarding the other “test ”—i. e. of our “immediate cognizance” of our bodily 
rocesses—it may first be noted that we are never “directly conscious ’’ of any of 
our bodily processes, not even of those curtical activities supposed most immedi- 
ately to underlie ovr conscious states. And next re should be noted that the 
question is not at all of our bei f any of t ‘or 
SR of certain activites ofe some of the lower nerve-centres of the spine) ; si 
not this more than of our being conscious of the psychic life of some other 
person or creature than ourselves. But the real question is: are these : 
themselves, attended by correspondent psychic states? That such states, if they 
exist, do not form a part of our personality, in those cases where their correspond- 
ing neural activities are momentarily shut-off from meddling with our cortical 
activities, should be no more surprising than that the conscious states of an- 
other man’s brain do not mix in our personality, his brain being shut off from 
