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Leituras pela manhã II

por beatriz j a, em 17.05.18



(problemáticas da Teoria da Evolução - fim, propósito, teleologia, teleonomia, mecanicismo, sentido e narrativa- excertos)



“the end is more constant than the means of attaining it.” (Russel, quoted by Stephen L. Talbott)


All biological activity, even at the molecular level, can be characterized as purposive and goal-directed. As a cell grows and divides, it marshals its molecular and structural resources with a remarkably skillful “wisdom.” It also demonstrates a well-directed, “willful” persistence in adjusting to disturbances. Everything leads toward fulfillment of the organism’s evident “purposes.”


The telos or end of teleological behavior, in other words, rather than being a goal “out there,” freely conceived by a reflective organism, may simply be the organism’s own completeness and wholeness — the fullness of its self-expression under all life conditions that present themselves. “Being-at-work-staying-itself” (a phrase used by the interpreter of Aristotle Joe Sachs) is one way to characterize the organism’s teleological activity. The manner in which specific end-directed performances are carried out — cell division, production of proteins, avoidance of predators — can all be understood as partial aspects of that self-expression. They all participate in the distinctive character — the qualitative and meaningful existence — of a particular kind of organism.


today the immaterial agent of change is more likely to be impounded in some such term as “tendency” or “pattern” or “mutation” (another way of saying “change”) or “norm” or (in more up-to-date biology) “code”, “message” or “information” — the whole change from e.g. a single cell to a complex living organism requiring no more than amino-acids and genes — plus, of course, an ability to code and decode, which last need not be unduly stressed.


“The trouble,” Barfield concludes, is that “particles as such ... cannot even arrange and rearrange themselves without more. Yet, if one credits them with immaterial ‘swerves’ or ‘tendencies’ and so forth, he has forgotten that those are the very things he was purporting to explain by them.”


What we have learned in all the foregoing is that, whether we are speaking of conscious human behavior in response to an accident, or the life cycle of a bird, or the molecular interactions through which genes are expressed, neither physical lawfulness nor any code-based “necessity” can lay bare for us the coherence, significance, and end-directedness through which we make sense of living activity. We grasp a biological context as such only in terms of its reasons, meanings, and purposiveness.



The problem of teleology, with its apparent inwardness, has been thought to present itself on two fronts. It occurs wherever a conscious, purposive designer, traditionally taken to be God, is assumed to have created organisms, and again wherever the organism itself, once created, becomes a locus of end-directed functioning. Resolving the issue of teleology has meant, for the biologist, eliminating inwardness on both fronts, and the argument often makes little distinction between them.



Everyone agrees that natural selection cannot work unless the organisms available to it are capable of carrying out all the activities necessary to their life and survival, while also reproducing and preparing an inheritance for their offspring. But these are the very activities that presented us with the problem of teleology in the first place. If natural selection must assume them in order to do its work, then to say it solves the problem of teleological origins looks very much like question-begging.



In 1962, the philosopher Grace de Laguna wrote a paper onThe Role of Teleonomy in Evolution in which she said of natural selection that it is only on organisms “as teleonomic systems that it can operate.” And, she explained, “only when we think in teleonomic terms, and regard the structure as end-directed, does it make sense to speak of ‘selection’ at all.”



The attempt to sustain the materialistic view based on a single half of the crudely dichotomized Cartesian world is a sickness from which contemporary thought cannot seem to free itself. Yet biologists, like all scientists, inevitably acknowledge an undivided world in one way or another. This is why the organism’s well-directed forming and organizing activities provide the very principles by which biologists themselves define relevant fields of inquiry. Cells must divide, proteins must be synthesized, signals must be sent, received, and interpreted — all depending on local contexts and the needs of the organism as a whole. If the researcher does not have a well-formed narrative — an end-directed achievement — to investigate, he does not have a biological project, as opposed to a chemical or physical one.



Evolution-based pronouncements have somehow become far too easy. When theorists can lightly pretend to have risen above the most enduring mysteries of life, making claims supposedly too obvious to require defense, then even questions central to evolution itself tend to disappear in favor of reigning prejudices. What is life? How can we understand the striving of organisms to sustain their own lives — a striving that seems altogether hidden to conventional modes of understanding? What makes for the integral unity and compelling “personality” of the living creature, and how can this personified unity be understood if we’re thinking in purely material and machine-like terms? Does it make sense to dismiss as illusory the compelling appearance of intelligent and intentional agency in organisms?


It is evident enough that the answers to such questions could crucially alter even our most basic assumptions about evolution. But we have no answers. In the current theoretical milieu, we don’t even have the questions. What we do have is the seemingly miraculous agency of natural selection, substituting for the only agency we ever actually witness in nature, which is the agency of living beings.


It is one thing to assert the undoubted reality of life’s evolution on earth. But if theories of evolution — proposals about how it has occurred — are the matter of real interest today, I hope the discussion above will suggest the value of a little humility on our part in the face of profound and unanswered questions.


Evolution and the Purposes of Life Stephen L. Talbott


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