1026 THE STRUCTURE OF EVOLUTIONARY THEORY
but often so buried in a confusing and contentious literature that the centrality of the
argument becomes lost in collegial frustration.
In short, I emphasize two major premises at the outset: (1) The concept of
constraint must be sharpened and restricted in meaning to a coherent set of causal
factors that can promote evolutionary change from a structuralist perspective
different from—in the helpful sense of "in addition to" or "in conjunction with, and
yielding interesting nonlinear conclusions in the amalgamation," rather than "in
opposition to"—the functionalist logic of Darwinian natural selection. (2) The
concept of constraint must include theoretically legitimate and factually important
positive meanings—i.e., constraints as directing causes of particular evolutionary
changes—rather than only the negative connotations of structural limitations that
prevent natural selection from crafting an alteration that would otherwise be favored
and achieved.
The passage from Job, needless to say, only provides an etymological
justification for this crucial positivity of meaning. The case for actual existence, and
important relative frequency, of these positive aspects then becomes the organizing
theme of this chapter. But etymology provides a good beginning, because we must
first establish the coherence of a case in language and logic before we can ask, with
appropriate clarity, whether nature assents to such a reasonable and testable
hypothesis.
The meanings and derivations of "constraint" are varied and complex. The Latin
root stringere means both to compress or to draw tight (the negative connotations),
but also to move, affect or touch (the positive aspects). The prefix con, meaning
"with" or "together," brings several items into the field of change or compression.
Thus, constraints can surely be negative—as when we toss a group of miscreants into
a jail cell in order to keep them close and restrict their movements. But constraints
can also be positive, as when we force a group of items into closer conjunction so that
their combined power and speed can grow and also become more focused in a
particular direction towards a definite goal—as in the increased speed of fluids in
narrowed pipes, according to Bernoulli's principle.
I do not deny that modern English usage favors the negative connotations—
hence my rationale for this introduction. But the positive meanings remain current,
and certainly sanctioned both historically and linguistically. I began with Elihu's
statement because, when I first studied the Bible as a teenager, this passage confused
me. I did not yet know the positive meaning of constraint, and therefore couldn't
figure out why Elihu, although practically bursting from his need to speak, felt so
constrained that he dared not do so (even though he did so in the very next verse!). Of
course, Elihu meant "constraineth" in the opposite and positive sense that his need
would force, or constrain, the desired result—and that his words would pour forth in
a definite and channeled direction, not as a random spewing. * This active sense
- Interestingly, the King James Bible (a 17th century document) uses the word
constraint ten times, nine in the positive sense of directing or forcing an action in a
particular way. The most popular of 20th century "updates," the Revised Standard Version,
keeps the word "constrains" in some passages, but often changes the King James entry to
"urge," "compel," or "make," to emphasize the obviously intended positive meaning.