268 
ject matter of these at present. My chief 
wish is to point out what, as I see them, they 
are historically; and to state in language not 
primarily biological, but rather psychological 
and logical, what I conceive to be the central 
one among them. 
When the man who is a biologist comes, as 
he sooner or later must come, upon the prob- 
lems of the “J;’ the “not-I,;’ the “ self,’ 
“ nersonality,’ “ potentiality,’ and the rest, he 
is doomed to almost complete failure in 
his attempt to deal with them unless he 
supplements, whole-heartedly and with much 
pains, the methods to which he is accus- 
tomed in his usual field and laboratory re- 
searches by at least some of the methods of 
the introspective psychologist, the logician 
and the metaphysician. The main reason why 
this is so is that our senses and our minds are 
just as truly instruments of research—parts 
of our laboratory equipment—as are our 
microscopes, our mother tongue, and our 
mathematical formule. Consequently to neg- 
lect to inform ourselves somewhat as to the 
principles of construction and mode of work- 
ing of these personal instruments is to be 
mere rule-of-thumb workmen, just as simi- 
lar neglect of the principles underlying 
our microscopes and language and mathe- 
matical formule would make us rule-of- 
thumb users of these means of research. The 
biologist who has given no attention to the 
way sense perception, and imagination, and 
rational process enter into a laboratory in- 
vestigation has no more claim to be consid- 
ered a genuinely scientific biologist than has 
a druggist’s clerk to be considered a genu- 
inely scientific chemist. 
When one passes beyond the state of the 
raw empiricist in the use of his personal 
tools of research he soon comes upon the 
retinue of questions raised by Professor 
Jennings, and finds himself face to face with 
such live historical questions as that of the 
meaning of radical empiricism; as that of 
what the real kernel of psycho-physics is; as 
that of what is actually at the bottom of 
the conception of “things-in-themselves,” of 
Berkeley’s esse est percipi, of Descartes’s 
SCIENCE 
[N.S. Von. XXXV. No. 894 
famous cogito dictum, of the Schoolmen’s 
endless troubles about matter and form, sub- 
stance and accident, of the early Church 
Fathers’ warrings over the Logos and the 
Trinity, of Plato’s Ideas, of the Chinese Bud- 
dhist’s Bodhisattva, of the Vedic poet’s deva 
and vasu, of the Melanesian’s Mana and of 
innumerable other words and phrases found 
wherever the deeper instincts and desires and 
strivings of human beings have found expres- 
sion in terms that mean any thing at all to 
other human beings. Vital knowledge of these 
matters does not imply vast learning. In 
these days when books on all subjects under 
heaven are almost as abundant and accessible 
as the leaves on the trees nothing is requisite 
to make every educated person informed in 
these regions beyond the recognition of how 
vital such knowledge is, and industry, econ- 
omy and discrimination in the use of his time. 
So much for the historical setting of the 
problems. Now a little as to what, substan- 
tively, the central one among them is. It is 
the two-fold problem as to just how all 
knowledge of nature, be it ordinary or scien- 
tific, is built up, and whether there is any 
knowledge whatever that does not contain, on 
the one hand, essential elements of sense per- 
ception, and, on the other hand, essential ele- 
ments that can not be derived from sense 
perception, but have their seat at deeper depths 
than sense. 
All I am going to say toward an answer to 
this question is this: If Professor Jennings 
will tackle again his exceedingly interesting 
questions of how long a “ pure line” may be, 
and how many knots there are in the web of 
organic existence, starting this time from the 
standpoint of the “standardized reality” sug- 
gested by me a few years ago, and will work 
at it as devotedly as he does at problems of 
animal behavior and genetics, he will find no 
more possibility of getting into the limbo he 
seems to be in over reincarnation than of get- 
ting ensnarled in the problem of whether 
there is anywhere in the universe a place in 
which cubes are spherical in shape. To be 
1<¢Tife from a Biologist’s Standpoint,’’ Pop- 
ular Science Monthly, August, 1909, p. 180. 
