Lightness and Brightness and Other Confusions

Ulf Klarén
Natural Experiences and Physical
Abstractions – On epistemology of
colour and light
We may, if we like, by reasonings unwind things back to – – [the] moving
clouds of swarming atoms which science calls the only real world.
But – – the world we feel and live in will be that which our ancestors and
we, by slowly cumulative strokes of choice, have extricated out of this – –
by simply rejecting certain portions of the given stuff. 6
– William James 7 1890
Colour and light are fundamental to our experience of an outer reality. Colour
and light are what we see; to see colour and light logically distributed in space
is to see. What we, however, without hindrance and so vividly experience is a
coherent, surrounding world full of life. Man is a living creature moving
around in a spatial, continuously changing world. His perceptual systems and
cognitive abilities receive their distinctive features from this fact.
The most important aspect of human experience is that perceptual patterns,
that can be perceived and understood as spatial, are given such an interpretation
in the mind. All senses contribute to the experience of the surrounding
world, but vision occupies a place apart in perception; vision provides a spatial
inner image.
Our vision is based on a continuous adaptation to the physical world, where
colour and light are perceived from endlessly varying spatial positions and
under continuously changing light conditions.
In colour research methodology has most often neglected the need for knowledge
about spatial visual perception. It has set out from surface colours in
even and uniform light, and although colour and light are mentally inseparable
in our experience of the world around, the mutual and dynamic relation
between colour and light experiences has not been given attention. As a con-
6
James 1890, pp 288–289.
7
American psychologist and philosopher, 1842–1910
16