ce is made to a lens or a mirror, language is sometimes used
which suggests that the writer's naivete is sufficiently gross to treat
these physical factors as if they were engaged in perceiving the sphere.
But as it is evident that the lens operates as a physical factor in
correlation with other physical factors--notably light--so it ought to
be evident that the intervention of the optical apparatus of the eye is
a purely non-cognitive matter. The relation in question is not one
between a sphere and a would-be knower of it, unfortunately condemned by
the nature of the knowing apparatus to alter the thing he would know; it
is an affair of the dynamic interaction of two physical agents in
producing a third thing, an effect;--an affair of precisely the same
kind as in any physical conjoint action, say the operation of hydrogen
and oxygen in producing water. To regard the eye as primarily a knower,
an observer, of things, is as crass as to assign that function to a
camera. But unless the eye (or optical apparatus, or brain, or organism)
be so regarded, there is absolutely no problem of observation or of
knowledge in the case of the occurrence of elliptical and circular
surfaces. Knowledge does not enter into the affair at all till _after_
these forms of refracted light have been produced. About them there is
nothing unreal. Light is really, physically, existentially, refracted
into these forms. If the same spherical form upon refracting light to
physical objects in two quite different positions produced the same
geometric forms, there would, indeed, be something to marvel at--as
there would be if wax produced the same results in contact
simultaneously with a cold body and with a warm one. Why talk about _the
real_ object in relation to _a knower_ when what is given is one real
thing in dynamic connection with another real thing?

The way of dealing with the case will probably meet with a retort; at
least, it has done so before. It has been said that the account given
above and the account of traditional subjectivism differ only verbally.
The essential thing in both, so it is said, is the admission that an
activity of a self or subject or organism makes a difference in the real
object. Whether the subject makes this difference in the very process of
knowing or makes it prior to the act of knowing is a minor matter; what
is important is that the known thing has, by the time it is known, been
"subjectified."

The objection gi