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Darwin-L Message Log 1:153 (September 1993)

Academic Discussion on the History and Theory of the Historical Sciences

This is one message from the Archives of Darwin-L (1993–1997), a professional discussion group on the history and theory of the historical sciences.

Note: Additional publications on evolution and the historical sciences by the Darwin-L list owner are available on SSRN.


<1:153>From junger@samsara.law.cwru.edu  Thu Sep 16 16:13:18 1993

Date: Thu, 16 Sep 93 17:10:14 EDT
From: junger@samsara.law.cwru.edu (Peter D. Junger)
To: darwin-l@ukanaix.cc.ukans.edu
Subject: A Selection of Passages from Ernst Mayr--for discussion purposes only

Here are some extracts from:  Ernst Mayr, TOWARD A NEW PHILOSOPHY OF
BIOLOGY, Observations of an Evolutionist.  Harvard University Press,
Cambridge: 1988.  I find much of this objectionable, but shall not raise
my objections at this time, other than to say that in Mayr it seems that
his Physics envy has become fixated upon the fact that almost all
"philosophies of science" are, in fact, philosophies of physics.

----------------------------------------------------------------------

>From Essay 2, "Cause and Effect in Biology"

{*29} . . . .

        _The Problem of Teleology_

    No discussion of causality is complete which does not come to
grips with the problem of teleology.  This problem had its beginning with
Aristotle's classification of causes, one of the categories being
"final" causes.  This category is based on the observation of the
orderly and purposive development of the individual from the egg to the
"final" state of the adult.  Final cause has been defined as "the cause
responsible for the orderly reaching of a preconceived ultimate goal."
All goal-seeking behavior has been classified as "teleological," but so
have many other phenomena that are not necessarily goal-seeking in
nature.

    Aristotelian scholars have rightly emphasized that Aristotle--by
training and interest--was first and foremost a biologist, and that it
was his preoccupation with biological phenomena which dominated his
ideas on causes and induced him to postulate final causes in addition to
the material, formal, and efficient causes.  Thinkers from Aristotle to
the present have been challenged by the apparent contradiction between a
mechanistic interpretation of natural processes and the seemingly
purposive sequence of events in organic growth, reproduction, and animal
behavior.  Such a rational thinker as Bernard (1885) has stated the
paradox in these words:

    There is, so to speak, a preestablished design of each being and
    of each organ of such a kind that each phenomenon by itself
    depends upon the general forces of nature, but when taken in
    connection with the others it {*30} seems directed by some
    invisible guide on the road it follows and led to the place it
    occupies.

      We admit that the life phenomena are attached to
    physicochemical manifestations, but it is true that the
    essential is not explained thereby; for no fortuitous coming
    together of physicochemical phenomena constructs each organism
    after a plan and a fixed design (which are foreseen in advance)
    and arouses the admirable subordination and harmonious agreement
    of the acts of life . . .  Determinism can never be [anything]
    but physicochemical determinism.  The vital force and life
    belong to the metaphysical world.

    What is the _x_, this seemingly purposive agent, this "vital
force," in organic phenomena?  It is only in our lifetime that
explanations have been advanced which deal adequately with this paradox.

    The many dualistic, finalistic, and vitalistic philosophies of
the past merely replaced the unknown _x_ by a different unknown _y_ or
_z_, for calling an unknown factor _entelechia_ or _e'lan vital_ is not
an explanation.  I shall not waste time showing how wrong most of these
past attempts were.  Even though some of the underlying observations of
these conceptual schemes are quite correct, the supernaturalistic
conclusions drawn from these observations are altogether misleading.

    Where, then, is it legitimate to speak of purpose and
purposiveness in nature, and where it is [_sic_] not?  To this question
we can now give a firm and unambiguous answer.  An individual who--to
use the language of the computer--has been "programmed" can act
purposefully.  Historical processes, however, _cannot_ act purposefully.
A bird that starts its migration, an insect that selects its host plant,
an animal that avoids a predator, a male that displays to a female--they
all act purposefully because they have been programmed to do so.  When I
speak of the programmed "individual," I do so in a broad sense.  A
programmed computer itself is an "individual" in this sense, but so is,
doing reproduction, a pair of birds whose instinctive and learned
actions and interactions obey, so to speak, a single program.

    The completely individualistic and yet also species-specific DNA
program of every zygote (fertilized egg cell), which controls the
development of the central and peripheral nervous systems, of the sense
organs, of the hormones, of physiology and morphology, is the _program_
for the behavior computer of this individual.

    Natural selection does its best to favor the production of
programs guaranteeing behavior that increases fitness.  A behavior
program that guarantees instantaneous correct reaction to a potential
food source, to a potential enemy, or to a potential mate will certainly
give greater fitness {*31} in the Darwinian sense than a program that
lacks these properties.  Again, a behavior program that allows for
appropriate learning and the improvement of behavior reactions by
various types of feedback gives greater likelihood of survival that a
program that lacks these properties.

    The purposive action of an individual, insofar as it is based on
the properties of its genetic code, therefore is no more nor less
purposive than the actions of a computer that has been programmed to
respond appropriately to various inputs.  It is, if I may say so, a
purely mechanistic purposiveness.

    We biologists have long felt that it is ambiguous to designate
such programmed, goal-directed behavior "teleological," because the word
_teleological_ has also been used in a very different sense, for the
final stage in evolutionary adaptive processes (see Essay 3).

    The development or behavior of an individual is purposive;
natural selection is definitely not.  When MacLeod (1957) stated, "What
is most challenging about Darwin, however, is his re-introduction of
purpose into the natural world," he chose the wrong word.  The word
_purpose_ is singularly inapplicable to evolutionary change, which is,
after all, what Darwin was considering.  If an organism is well adapted,
if it shows superior fitness, this is not due to any purpose of its
ancestors or of an outside agency, such as "Nature" or "God," that
created a superior design or plan.  Darwin "has swept out such
finalistic teleology by the front door," as Simpson (1960) has rightly
stated.

    We can summarize this discussion by stating that there is no
conflict between causality and teleonomy, but that scientific biology
has not found any evidence that would support teleology in the sense of
various vitalistic or finalistic theories (Simpson 1960; 1950; Koch
1957).  All the so-called teleological systems which Nagel discusses
(1961) are actually illustrations of teleonomy.

-----------------------------------------------------------------------

>From Essay 3, "The Multiple Meanings of Teleological"

{*39}

_Traditional Objections to the Use of Teleological Language

    Criticism of the use of teleological language is traditionally
based on one or several of the following objections.  In order to be
acceptable teleological language must be immune to these objections.

{*40} _(1)  Teleological statements and explanations imply the
endorsement of unverifiable theological or metaphysical doctrines in
science._  This criticism was indeed valid in former times . . . .
Contemporary philosophers reject such teleology almost unanimously.
Likewise, the employment of teleological language among modern
biologists does not imply adoption of such metaphysical concepts (see
below).

    _(2)  The belief that acceptance of explanations for biological
phenomena that are not equally applicable to inanimate nature
constitutes rejection of a physicochemical explanation._  Ever since the
age of Galileo and Newton it has been the endeavor of the "natural
scientists" to explain everything in nature in terms of the laws of
physics.  To accept special explanations for teleological phenomena in
living organisms implied for these critics a capitulation to mysticism
and a belief in the supernatural.  They ignored the fact that nothing
exists in inanimate nature (except for man-made machines) which
corresponds to DNA programs or to goal-directed activities.  As a matter
fact, the acceptance of a teleonomic explanation (see below) is in no
way in conflict with the laws of physics and chemistry.  It is neither
in opposition to a causal interpretation, nor does it imply an
acceptance of supernatural forces in any way whatsoever.

    _(3)  The assumption that future goals were the cause of
current events seemed in complete conflict with any concepts of
causality._  Braithwaite (1954) stated the conflict as follows:  "In a
[normal] causal explanation the explicandum is explained in terms of a
cause which either precedes it or is simultaneous with it; in a
teleological explanation the explicandum is explained as being causally
related either to a particular goal in the future or to a biological end
which is as much future as present or past."  This is why some logicians
up to the present distinguish between causal explanations and
teleological explanations.

    _(4)  Teleological language seemed to represent objectionable
anthropomorphism._  The use of terms like _purposive_ or _goal-directed_
seemed to imply the transfer of human qualities such as intent, purpose,
planning, deliberation, or consciousness, to organic structures and to
subhuman forms of life.

{*41} Intentional, purposeful human behavior is, almost by definition,
teleological.  Yet I shall exclude it from further discussion because
use of the words _intentional_ or _consciously premeditated_, which are
usually employed in connection with such behavior, runs the risk of
getting us involved in complex controversies over psychological theory,
even though much of human behavior does not differ in kind from animal
behavior.  The latter, although usually described in terms of stimulus
and response, is also highly "intentional," as when a predator stalks
his prey or when the prey flees from the pursuing predator.  Yet,
seemingly "purposive," that is, goal-directed behavior in animals can be
discussed and analyzed in operationally definable terms, without
recourse to anthropomorphic terms like _intentional_ or _consciously_.

    . . . .

    The teleological dilemma, then, consists in the fact that
numerous and seemingly weighty objections against the use of
teleological language have been raised by various critics, and yet
biologists have insisted that they would lose a great deal,
methodologically and heuristically, if they were prevented from using
such language.  It is my endeavor to resolve this dilemma by a new
analysis, and particularly by a new classification of the various
phenomena that have been traditionally designated as teleological.

    . . . .

{*44} . . . .

      _SEEMINGLY OR GENUINELY GOAL-DIRECTED PROCESSES_

    Nature (organic and inanimate) abounds in processes and
activities that lead to an end.  Some authors seem to believe that all
such terminating processes are of one kind and "finalistic" in the same
manner and to the same degree.  Taylor (1950), for instance, if I
understand him correctly, claims that all forms of active behavior are
of the same kind and that there is no fundamental difference between one
kind of movement or there is no fundamental difference between one kind
of movement or purposive action and any other.  Waddington (1968) gives
a definition of his term _quasi-finalistic_ as requiring "that the end
state of the process is determined by its properties at the beginning."

    Further study indicates, however, that the class of end-directed
processes is composed of two entirely different kinds of phenomena.
These two types of phenomena may be characterized as follows:

    _Teleomatic processes in inanimate nature._  Many movements of
inanimate objects as well as physicochemical processes are the simple
consequences of natural laws.  For instance, gravity provides the
end-state for a rock which I drop into a well.  It will reach its
end-state when it has come to rest on the bottom.  A red-hot piece of
iron reaches its end-state when its temperature and that of its
environment are equal.  All objects of the physical world are endowed
with the capacity to change their state, and these changes follow
natural laws.  They are end-directed only in a passive, automatic way,
regulated by external forces or conditions.  Since the end-state of such
inanimate objects is automatically achieved, such changes might be
designated as _teleomatic_.  All teleomatic processes come to an end
when the potential is used up (as in the cooling of a heated piece of
iron) or when the process is stopped by encountering an external
impediment (as a falling stone hitting the ground).  Teleomatic
processes simply follow natural laws, i.e. lead to a result
consequential to concomitant physical forces, and the reaching of their
end-state is not controlled by a built-in program.  The law of gravity
and the second law of thermodynamics are among the natural laws which
most frequently govern teleomatic processes.

    _Teleonomic_ processes in living nature._  Seemingly goal
-directed behavior by organisms is of an entirely different nature from
teleomatic processes.  {*45} Goal-directed _behavior_ (in the widest
sense of this word) is extremely widespread in the organic world; for
instance, most activity connected with migration, food-getting,
courtship, ontogeny, and all phases of reproduction is characterized by
such goal orientation.  The occurrence of goal-directed processes is
perhaps the most characteristic feature of the world of living
organisms.

    For the last 15 years or so the term _teleonomic_ has been used
increasingly often for goal-directed processes in organisms.  I proposed
in 1961 the following definition for this term:  :It would seem useful
to restrict the term teleonomic rigidly to systems operating on the
basis of a program, a code of information" (Mayr 1961)  Although I used
the term _system_ in this definition, I have since become convinced that
it permits a better operational definition to consider certain
activities, processes (like growth), and active behaviors as the most
characteristic illustrations of teleonomic phenomena.  I therefore
modify my definition, as follows:  _A teleonomic process or behavior is
one which owes its goal-directedness to the operation of a program._
The term teleonomic implies goal direction.  This, in turn, implies a
dynamic process rather than a static condition, as represented by a
system.  The combination of teleonomic with the term system is, thus,
rather incongruent (see below).

    All teleonomic behavior is characterized by two components.  It
is guided by a "program," and it depends on the existence of some end,
goal, or terminus which is foreseen in the program that regulates the
behavior.  This endpoint might be a structure, a physiological function,
the attainment of a new geographical position, or a "consummatory"
(Craig 1918) act in behavior.  Each particular program is the result of
natural selection, constantly adjusted by the selective value of the
achieved end-point.

    My definition of _teleonomic_ has been labeled by Hull (1974) as
a "historical definition."  Such a designation is rather misleading.
Although the genetic program (as well as its individually acquired
components) originated in the past, this history is completely
irrelevant for the functional analysis of a [sic] given teleonomic
processes.  For this it is entirely sufficient to know that a "program"
exists which is causally responsible for the teleonomic nature of a
goal-directed process.  Whether this program had originated through a
lucky macromutation (as Richard Goldschmidt had conceived possible) or
through a slow process of gradual selection, or even through individual
learning or conditioning as in open programs, is quite immaterial for
the classification of a process as "teleonomic."  On the other {*46}
hand, a process that does not have a programmed end does not qualify to
be designated as teleonomic (see below for a discussion of the concept
_program_).

    All teleonomic processes are facilitated by specifically
selected executive structures.  The fleeing of a deer form a predatory
carnivore is facilitated by the existence of superlative sense organs
and the proper development of muscles and other components of the
locomotory apparatus.  The proper performing of teleonomic processes at
the molecular level is made possible by highly specific properties of
complex macromolecules.  It would stultify the definition of
_teleonomic_ if the appropriateness of these facilitating executive
structures were made part of it.  On the other hand, it is in the nature
of a teleonomic program that it does not induce a simple unfolding of
some completely preformed gestalt, but that it always controls a more or
less complex process which must allow for internal and external
disturbances.  Teleonomic processes during ontogenetic development, for
instance, are constantly in danger of being derailed even if only
temporarily.  There exist innumerable feedback devices to prevent this
or to correct it.  Waddington (1957) has quite rightly called attention
to the frequency and importance of such homeostatic devices which
virtually guarantee the appropriate canalization of development.

    We owe a great debt of gratitude to Rjosenblueth et al. (1943)
for their endeavor to find a new solution for the explanation of
teleological phenomena in organisms.  They correctly identified two
aspects of such phenomena:  (10) that they are seemingly purposeful,
being directed toward a goal, and (2) that they consist of active
behavior.  The background of these authors was in the newly developing
field of cybernetics, and it is only natural that they should have
stressed the fact that goal-directed behavior is characterized by
mechanisms which correct errors committed during the goal seeking.  They
considered the negative feedback loops of such behavior as its most
characteristic aspect and stated "teleological behavior, yet it misses
the crucial point:  _The truly characteristic aspect of goal-seeking
behavior is not that mechanisms exist which improve the precision with
which a goal is reached, but rather that mechanisms exist which
initiate, i.e. "cause" this goal-seeking behavior.  It is not the
thermostat which determines the temperature of a house, but the person
who set the thermostat.  It is not the torpedo which determines toward
what ship it will be shot and at what time, but the naval officer who
releases the torpedo.  Negative feedback only improves the precision of
goal-seeking, but does not determine it.  {*47} Feedback devices are
only executive mechanisms that operate during the translation of a
program.

    Therefore it places the emphasis on the wrong point to define
teleonomic processes in terms of the presence of feedback devices.  They
are mediators of the program, but as far as the basic principle of goal
achievement is concerned, they are of minor consequence.

    . . . .

Peter D. Junger

Case Western Reserve University Law School, Cleveland, OH
Internet:  JUNGER@SAMSARA.LAW.CWRU.Edu -- Bitnet:  JUNGER@CWRU

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