Biology Reference
In-Depth Information
existence of three different cone photopigments situated in different
cones have resulted in a transformation of the basic assumption of
Young's colour theory from a theoretical to a
factual
status. There is,
of course, no room for such a transformation in Popper's model.
Our description of the development of the duplicity
theory is not easily reconciled with Kuhn's model either. Thus,
in apparent contrast to Kuhn's account of scientific progress,
the development of the duplicity theory has been marked by a
series of important steps that all still are regarded as milestones
in our understanding of visual phenomena. In fact, no so-called
crises and revolutions, where one paradigm is abandoned and
another adopted, are apparent. Instead, the steps taken appear to
complement each other and may therefore exist simultaneously.
Of course, an understanding of Kuhn's model depends to a large
extent on how the concept 'paradigm' is interpreted. Yet, even if it
is asserted that there has been no paradigm shift in vision research
since Newton, one would have to admit that great discoveries and
large progressive steps in the development of the duplicity theory
have occurred and that, therefore, his characteristics of so-called
'normal science' would not be met. Also, the sharp differences in
opinion between Hecht, Wald, Rushton, Barlow and Lamb in the
twentieth century, where relatively little fundamental change has
occurred in the development of the duplicity theory (and on these
grounds might be characterized as a 'normal' scientific period),
are not in accord with Kuhn's description where he emphasizes
an uncritical and devoted attitude toward the ruling paradigm.
Instead, the leading authorities have attempted to build their own
theories on rational grounds, mainly in conflict with each other.
Similar considerations apply for the period between Newton and
Young.
Moreover, there is at present no indication that a single paradigm
will emerge and dominate vision research. Contrary to this view, the
scientific progress in vision research appears to move simultaneously
in several different directions, focusing on visual processing at various
