ves a convenient occasion for summarizing the main
points of the argument. On the one hand, the retort of the objector
depends upon talking about _the_ real object. Employ the term "_a_ real
object," and the change produced by the activity characteristic of the
optical apparatus is of just the same kind as that of the camera lens or
that of any other physical agency. Every event in the world marks a
difference made to one existence in active conjunction with some other
existence. And, as for the alleged subjectivity, if subjective is used
merely as an adjective to designate the specific activity of a
particular existence, comparable, say, to the term feral, applied to
tiger, or metallic, applied to iron, then of course reference to
subjective is legitimate. But it is also tautological. It is like saying
that flesh eaters are carnivorous. But the term "subjective" is so
consecrated to other uses, usually implying invidious contrast with
objectivity (while subjective in the sense just suggested means specific
mode _of_ objectivity), that it is difficult to maintain this innocent
sense. Its use in any disparaging way in the situation before us--any
sense implicating contrast with a real object--assumes that the organism
_ought_ not to make any difference when it operates in conjunction with
other things. Thus we run to earth that assumption that the subject is
heterogeneous from every other natural existence; it is to be the one
otiose, inoperative thing in a moving world--our old assumption of the
self as outside of things.[10]

What and where is knowledge in the case we have been considering? Not,
as we have already seen, in the production of forms of light having a
circular and elliptical surface. These forms are natural happenings.
They may enter into knowledge or they may not, according to
circumstances. Countless such refractive changes take place without
being noted.[11] When they become subject-matter for knowledge, the
inquiry they set on foot may take on an indefinite variety of forms. One
may be interested in ascertaining more about the structural
peculiarities of the forms themselves; one may be interested in the
mechanism of their production; one may find problems in projective
geometry, or in drawing and painting--all depending upon the specific
matter-of-fact context. The forms may be _objectives_ of knowledge--of
reflective examination--or they may be means of knowing something else.
It may happen--under so