Internalism and Laws of Form 341
of variation (shapes of stones) "bear no relation to the living structure which is
slowly built up" (the form of the building). An architect, armed with a blueprint
and enough stones, can build the desired structure, whatever the shapes of pieces
available for construction. Thus, "variability sinks to a quite subordinate position
in importance in comparison with selection."
Throughout this chapter and elsewhere I have spoken of selection as the
paramount power, yet its action absolutely depends on what we in our
ignorance call spontaneous or accidental variability. Let an architect be
compelled to build an edifice with uncut stones, fallen from a precipice.
The shape of each fragment may be called accidental; yet the shape of each
has been determined by the force of gravity, the nature of the rock, and the
slope of the precipice—events and circumstances, all of which depend on
natural laws; but there is no relation between these laws and the purpose for
which each fragment is used by the builder. In the same manner the
variations of each creature are determined by fixed and immutable laws;
but these bear no relation to the living structure which is slowly built up
through the power of selection, whether this be natural or artificial
selection.
If our architect succeeded in rearing a noble edifice, using the rough
wedge-shaped fragments for the arches, the longer stones for the lintels and
so forth, we should admire his skill even in a higher degree than if he had
used stones shaped for the purpose. So it is with selection, whether applied
by man or by nature; for though variability is indispensably necessary, yet,
when we look at some highly complex and excellently adapted organism,
variability sinks to a quite subordinate position in importance in
comparison with selection, in the same manner as the shape of each
fragment used by our supposed architect is unimportant in comparison with
his skill (1868, vol. 2, pp. 248-249).I suggest, as a major theme of this book, that Darwinian evolutionists, ever
since, have placed too much confidence in this edifice. Darwin's metaphorical
structure, fully shaped by the architect of natural selection, cannot be dismissed as
a house of cards, but the walls have developed some cracks and may even be ripe
for a breach.