The World as Percept 57and light. Others fail to perceive only a specific color,
such as red. Their image of the world lacks this hue, and
is therefore actually different from that of the average hu-
man being. I should like to call the dependence of my
perceptual image on my place of observation a “mathe-
matical” one, and its dependence on my organization a
“qualitative” one. The relative sizes and distances of my
percepts are determined through the former; their quality
through the latter. That I see a red surface as red—this
qualitative determination—depends on the organization
of my eye.
Initially, then, our perceptual images are subjective.
This recognition of the subjective character of our per-
cepts can easily lead us to doubt whether anything objec-
tive underlies them at all. If we know that a percept, for
example the color red or a particular sound, is only possi-
ble thanks to the structure of our own organism, then we
can easily come to believe that the percept does not exist
outside our subjectivity, and that apart from the act of per-
ceiving, whose object it is, it has no kind of existence. This
view found its classic expression in George Berkeley, who
believed that as soon as we become aware of the impor-
tance of the subject for percepts, we can no longer believe
in a world that exists apart from the conscious spirit:
Some truths are so near and so obvious to the
mind that man need only open his eyes to see them.
Such I take this important truth to be, to wit, that
all the choir of heaven and furniture of the earth, in
a word, all those bodies which compose the mighty
frame of the world, have not any subsistence with-