CHAP. II.
SECT. VI.

Proper meaning

and object

of perception.

In

may ask, what is the relation between the x of one
quality and that of another? Is the x of light, for
example, or a particular colour, the same as the x of
heat? Is the x of smell the same as the x of taste?
Or is there only one a for all qualities, which
coming into relation with our organism gives rise
to the different kinds of sensations of which we are
conscious? These are some of the questions which
may be proposed in connection with this subject, and
we refer to them here, chiefly for the purpose of
setting them aside. They are not questions which
it is the business of the psychologist to answer.
so far as they can be answered, they belong to the
sphere of experimental physics or of metaphysics: in
so far as they are insoluble, they should be left alone
altogether. As far as psychology is concerned, we
are confined to the analysis and synthesis of our
conscious knowledge; and in perception the object
of our knowledge is the sensible world-that is,
the world revealed to us through our senses. Out-
side, or behind this sensible world, we cannot go,
either in perception or in imagination.* The un-
known a of sensible qualities is not only incapable
of being perceived, but also as x of being conceived.
And as in psychology we are concerned only with
what can be known, questions regarding the unknown
are referred to only to point them out as irrelevant.

§ 38. We are now in a position to understand clearly what we mean by the object of perception. From what we have seen, it is manifest that

* We may, however, as we shall afterwards see, by inference.

And

We can say is, we recogThus percep

perception is the act only of educated senses.
those who identify perception with consciousness must
mean by it something different from what is usually
meant by the word. The object of perception must
be at a greater or less distance from the sentient
organism. Its existence is made manifest by a
sensation of colour or some other. That sensation is,
as we have seen, transferred outwards in a particular
direction and to some particular distance. We see
the object. But sight gives us nothing but colour
and figure; these qualities are, however, connected
in our minds, in consequence of past experiences,
with other qualities. And if we have before seen
the object, we are able to predict what other sensa-
tions it is capable of giving rise to.
how it will feel, smell, taste, &c., that
nise the object, and give it a name.
tion implies at least one actual sensation, and several
other ideal ones connected with it; implies also a
belief that these ideal sensations will become actual,
if the necessary physical conditions are fulfilled.
Now the sensible world, in perception, is separated
from the mind, although in the analysis of the pro-
cess of perception we have seen that this separation
is not a real one. The sensible world is partly the
creation of the conscious mind; and, in the study of
psychology, it must ever be borne in mind that the
objects of that world combine in themselves both
subjective and objective elements-partake both of
the ego and the non-ego. In the study of the par-
ticular sciences, however, such as optics, acoustics,

CHAP. II.

SECT. VI.

CHAP. II.

SECT. VI.

mineralogy, botany, as well as in the ordinary affairs of life, it is quite legitimate, and, indeed, necessary, to bestow independent existence upon the objects of the senses. This is done for us naturally in the education which our senses receive; and the study of objective science does not require us to leave the stand-point of practical life while the study of psychology does.

CHAP. III.
SECT. I.

CHAPTER III.

THEORIES OF PERCEPTION.

SECTION I.

GENERAL DESCRIPTION AND CLASSIFICATION.

troduced.

§ 39. In order to have a clear understanding of Subject inany theory of perception, it is necessary to compare it with, and distinguish it from, other theories from which it to a greater or less extent may differ. And in this chapter we propose to bring together, for the purpose of comparison, the most important theories regarding this subject which have been held by philosophers. In the early history of philosophy, the different departments of study were not clearly distinguished from one another. In the writings of the Grecian philosophers, there were frequently collected together, in a confused manner, discussions on psychological, cosmological, theological, ethical, and logical questions; and a greater or less confusion of questions, that ought to be separately examined, may be found throughout the whole history of philosophy. It is natural that in the early stages of human knowledge there should be this confusion; but it is necessary to the progress of knowledge that this confusion should be cleared away. It is chiefly

CHAP. III.

SECT. I.

Two points of view.

in modern times, and specially since the time of Descartes, that we find the original chaos of human knowledge becoming separated into clearly defined sciences. We shall therefore look for the theories of perception, which we wish to examine only in the history of modern philosophy, from the time of Descartes, as in that period we are likely to find the clearest statements of the results of investigation into the nature of our knowledge of external things.

Before proceeding to examine any of the particular theories which have been held regarding perception, we propose to take a general view of certain fundamental differences between these theories, by means of which we may arrange them into classes. The possibility of making a classification assumes, of course, a knowledge more or less complete of the things to be classified, and the reader must therefore take for granted the accuracy of our general descriptions until he is able to verify them by the study of the special theories to which they may be applied.

§ 40. There are two distinct points of view from which the student of the process of perception may proceed in the examination of his knowledge. It is difficult to find any single unambiguous word which indicates these points of view respectively, and therefore, without in the meantime naming them, we shall proceed to describe them at length.

(1) From the first stand-point, the psychologist regards the objects of the world of sense as having an existence independent of the mind; and the