Download Darwin after Malthus

Darwin after Malthus
DOV OSPOVAT
University
Lincoln,
of Nebraska
Nebraska
In the Origin of Species (1859) natural selection is presented as an
autonomous biological process which is, potentially, in continuous
operation. No organism is perfect. There is always room for improvement. At any time or place a species, however well adapted it may seem
to be, may give rise to still better-adapted forms. New variations may
appear that are better suited for existing conditions, and when this
happens the pressure of population will work to select them and their
similarly favored offspring until a new, improved form is created.
Natural selection, Darwin said in the Origin, is “daily and hourly
scrutinising, throughout the world, every variation”; it is “silently
and insensibly working, whenever and wherever opportunity offers,
at the improvement of each organic being in relation to its organic and
inorganic conditions of life.” * In the “Essay of 1844,” on the other
hand, selection is depicted as confined and limited in its operation.
Compare the statement I have just quoted with this description of the
evolutionary process from the “Essay”: if there are variation and struggle in nature, then “new races of beings will, - perhaps only rarely, and
only in some few districts, - be formed.“2
One’s first reaction is probably to dismiss this contrast by saying
that in 1844 Darwin was less confident or merely more cautious in his
exposition. But there is much more to it than this. In 1844 natural
selection was limited by what I would like to call structural constraints,
which were eliminated sometime before 1859. By structural constraints
I mean those imposed by the framework of beliefs about nature within
which Darwin supposed that his evolutionary mechanism operated. To
be more precise, Darwin in 1844 still believed in perfect adaptation.
Perfectly adapted forms are not capable of further improvement. They
vary little; so, among them, natural selection has little material on
1. Charles Darwin, On the Origin of Species (London: John Murray, 1859),
p. 84.
2. Francis Darwin, ed., The Foundations
of the Origin
of Species:
Two
Essays
Written
in 1842 and 1844 by Charles
Darwin
(Cambridge: Cambridge
University Press, 1909), 1844, p. 109.
Journal
of the History
0022-5010/79/0122-0211
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0 1979
vol. 12, no. 2 (Fall 1979), pp. 211-230.
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of Biology,
by D. Reidel
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and Boston,
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DOV
OSPOVAT
which to work. The checks caused by population pressure fall evenly on
all, except for occasional misfits, which are weeded out. Consequently,
the action of natural selection is restricted to a few situations - those
in which there is geological change, or those in which organisms are
transported into new regions, so that they are no longer perfectly
adapted, The idea of perfect adaptation, which Darwin shared with
most of his contemporaries, had its roots not in the naturalist’s examination of organisms, but in his belief that organisms were created either directly or indirectly - by a wise and benevolent God. This
belief also Darwin shared for some time with most of his contemporaries; and even after he began to modify it, he continued to suppose
that organisms are perfectly adapted. In short, for a number of years,
Darwin conceived of natural selection as operating in an essentially
natural theological framework.
The fact that Darwin continued to believe in perfect adaptation
from his pre-Malthus period until after 1844 will require, I think, a new
analysis of the character and development of Darwin’s theory. But since
it has not been noticed before, and has been implicitly denied by most
Darwin scholars who have discussed the problem of adaptation, the first
task must be to establish the fact. That is the limited aim of this paper.
It will, perhaps, be best to begin with my conclusions, because the
argument will then be easier to follow. First: Until he read Malthus, at
the end of September 1838, Darwin believed that adaptation is perfect
and that the universe is a harmonious whole. This, I must note, was
David Kohn’s conclusion before it was mine.3 I find his arguments on
this point unassailable, and I am convinced that Darwin’s notebooks
admit of no other interpretation. Second: When Darwin read Malthus
and hit upon the idea of natural selection4 he did not immediately
3. E. David Kohn,
“Charles
Darwin’s
Path to Natural
Selection,”
Ph.D. diss.,
University
of Massachusetts,
1975.
4. I use the term natural
selection
for the sake of convenience,
but it should
be borne in mind that at first Darwin
spoke only of “wedging,”
not “selection”
or
“picking.”
Gavin de Beer, et al., eds., “Darwin’s
Notebooks
on Transmutation
of
Species. Part VI. Pages Excised
by Darwin,”
Bull. Brit. Mus. (Nat. Hist.), Hist. Ser.,
3 (1967),
131-176.
All references
to Darwin’s
notebooks
will be to the de Beer
edition, ibid., 2 (1960),
41-183,3
(1967),
131-176.
De Beer’s “First,”
“Second,”
“Third,”
and “Fourth”
notebooks
correspond
to Darwin’s
B, C, D, and E note
books. Throughout
I will cite the notebooks
by Darwin’s
letter and page number,
followed
by a small e in the case of excised pages: in the present
instance,
D, p.
135e. Camille
Limoges
in La sdection naturelle (Paris: Presses Universitaires
de
France,
1970), pp. 104-105,
notes that as far as he has found, the earliest use by
Darwin
of the term “selection”
is in marginal
annotations
of W. Youatt’s
Cattle,
212
Darwin after Malthus
abandon his belief in perfection and harmony.5 Although he would
later do so, he did not immediately view the organic world as a scene of
struggle and discord, productive only of relatively, that is, less-thanperfectly, adapted creatures. Instead, he initially envisaged natural
selection as operating in precisely the same natural theological context
in which Malthus had set his principle of population - the context of
a system of beneficent laws. Third: Within a few months of reading
Malthus, Darwin gave up the idea that every natural effect of nature’s
laws was included in the original design for which the whole system of
laws was established. But he continued until some time after 1844 to
believe in perfect adaptation, and this determined the structure of his
entire theory in its early years. In the “Essaapiof 1844” that structure is
the same one that Darwin laid down in his first transmutation notebook,
at a time when he still adhered to traditional views on the harmony of
the creation.
My argument falls into three parts, corresponding roughly to these
three conclusions. In the first, it is necessary to explain in what sense
Darwin throughout his pre-Malthus notebooks believed in harmony and
perfection, for it is fairly widely held that he rejected such notions
some time before September 1838.‘j In the second part 1 examine
Darwin’s reaction to Malthus, in order to indicate how Darwin initially
fit his new theory into his old framework of beliefs. And in the third I
attempt to show the persistence, in the “Essay of 1844,” of the idea of
perfect adaptation and of the theoretical structure that from the first
was associated with it.
DARWIN BEFORE MALTHLJS
When I say that Darwin believed in perfect adaptation, I must at
once introduce a distinction. Darwin, it is true, rejected the PaleyBreeds, Management
and Disease (18341, which Darwin read in March 1840.
The earliest I have seenis in a loose note dated “Jan 1840”; Darwin MS& Box B,
C40f, CambridgeUniversityLibrary.
Their
5. It is here that I part company
with David Kohn. I must point out also that
Kohn and I are not entirely
in agreement
about
the reasons for Darwin’s
preMalthus
belief in perfect
adaptation.
6. Most
notably
by Camille Limoges, S&ection
naturelle,
pp. 69-85,
and
“Darwinisme
et adaptation,”
Revue des Questions
Scientifiques,
141, 5th ser., 31
(19701,
353-374.
See also Silvan Schweber,
“The Origin of the Origin Revisited,”
J Hist. Biol,
10 (1977),
235; Sandra
Herbert,
“Man in the Development
of
Darwin’s
Theory
of Transmutation,
Part II,” ibid., p. 200; and Howard
Gruber,
Darwin
on Man (New York:
E. P. Dutton,
1974), p. 158.
213
DOV OSPOVAT
Bridgewater variety of perfect adaptation long before he read Malthus.
For Charles Bell, William Buckland, or Charles Lye& as for Cuvier,
adaptation to purpose was the only acceptable explanation of organic
structure. When Darwin became a transmutationist, he of necessity
became an opponent of their “principle of adaptation,” for it is strictly
incompatible with the theory of descent.’ But the Bridgewater variety
of perfect adaptation was not the only possible one. I have pointed
out elsewhere that, like Darwin, many biologists from the 1830’s
through the 1850’s repudiated the teleological approach of Bell and
Cuvier while retaining a belief in perfect adaptation.8 They argued that
there are structural similarities among organisms that cannot be explained satisfactorily in purely functional terms and that consequently
one must recognize a law of unity of type. Organisms are as perfect as is
possible within the limits set by the necessity of conforming to the
type.9 Their perfection is part of a “teleology of a higher order,” which
is to say that it is produced by a system of laws established by God.”
Here, for instance, is Richard Owen’s idea of perfection
as he expressed
it in 1838:
It is a groundless fear that some have expressed when a physical explanation of the form and condition of an organ has been offered, that
it blunts
our appreciation
of the Wisdom
which
adapted
that organ
I. While the “principle of adaptation” allows no other explanation but
adaptation, in all descent theories heredity is a major part of the explanation of
structure. The inadequacy of the principle of adaptation is a constant theme in
the transmutation notebooks (it is this that Limoges and Gruber, in the works
cited above, have interpreted as a rejection of perfect adaptation - which is only
partly true). Darwin insists that adaptation alone cannot explain unity of type,
rudimentary organs, geographical distribution, or the relation of recent with
extinct animals in the same continent, although adaptation plus heredity can do
so. See, e.g., B, pp. 12-15, 4647, 84, 98-99, 110-117, 130, 193-194, and C, pp.
76-17,99.
8. “Perfect
Adaptation and Teleological Explanation: Approaches to the
Problem of the History of Life in the Mid-Nineteenth Century,” Sfud. H&r. Biol.,
2 (1978), 33-56.
9. This is only one of several sorts of “laws” that antiteleologists pointed to as
being incompatible with the strictly teleological approach. Others include the lawr
of geographical distribution and geological succession. See, e.g., Louis Agassiz.
Essay
on Classification
(London: Longman, Brown, Green, Longmans, and
Roberts and Trubner, 1859), chap. 1, where the teleological approach is criticized
at length.
10. [Richard Owen], “Generalizations
of Comparative Anatomy,” Quart.
Rev.,
93 (1853), 80; see also William B. Carpenter, Principles
of General
ana
Compurative
Physiology
(London: John Churchill, 1839), p. 461.
214
Darwin after Malthus
to its special office. On the contrary - the higher and more general
are the laws regulating the structure of animals of which we can
obtain a conception, the more will the Contemplative Mind be
struck with the vastness of that designing intelligence which in
originally ordaining them could produce such harmony and adaptation amongst their innumerable results.”
According to such a view as this, the creator established laws in order to
produce just those phenomena in this world that he desired, and it is
from this, rather than a “principle of adaptation,” that the phenomena
derive their perfection,. This is neither a doctrine of relative nor of
imperfect adaptation. It is rather a doctrine of perfection limited by
general laws. This was also Darwin’s view until he read Malthus.12
Darwin denied that organisms are “so closely adapted” as the teleologists assumed. l3 But he held that the product of transmutation
is “complete adaptation.” l4 He imagined a great hierarchy of causes
subordinate to causes, down to “certain laws of harmony” by which
organisms “keep perfect.” l5 Together, the organic and inorganic
worlds, with all their changes, constituted, in Darwin’s words,a “system
of great harmony.” r6 So, while Darwin and many of his contemporaries
abandoned the teleological interpretation of perfection characteristic
of the school of Paley, they continued to share with that school a
general view of the world, that it is a harmonious system, the creation
of a benevolent God.
Darwin’s adherence to the harmonious view of nature, which nowhere appears more clearly than in the weeks just before he read
Malthus,” was not merely an unimportant survival from that youthful
period when he was captivated by Paley’s arguments. On the contrary, it
informs the whole of his early speculations on transmutation. Darwin’s
11. Richard
Owen MSS, Hunterian
Lectures
for 1838, Royal College of Surgeons.
12. This was first suggested
to me by Kohn’s
study. He argues that throughout the pre-Malthus
period,
Darwin’s
concept
of adaptation
was a revision,
rather
than a rejection,
of the Paleyan
idea of perfect
adaptation
(“Path
to Natural
Selection,”
pp. 84-87,
157). My own study
of the notebooks
confirms
that
Darwin’s
pre-Malthus
position
was identical
to the antiteleological
version
of
perfect
adaptation
I described
in “Perfect
Adaptation,”
cited above.
13. B, p. 130.
14. B, p. 210e.
15. D, pp. 36-37.
16. D, p. 74e.
17. D, pp. 36-37 (Aug. 16, 1838); D, p. 74e (Sept. 8, 1838).
21.5
DOV
OSPOVAT
usual way of proceeding in the transmutation notebooks was to inquire
“what is the final cause” of each mechanism or process he examined.
The final cause of transmutation was, for Darwin, the maintenance of
harmony; and the principal problem he set himself was to find the
means by which adaptation is preserved amidst the changes of the
external world. This is the burden of the opening pages of the B notebook. Darwin was convinced from an early stage that the key to the
solution was the process of generation. His argument for this is in
the form of an answer to the question: what is the purpose of generation? l8 We know, he said, that the world goes through cycles of changes
in temparature and all the circumstances that influence living beings.
Full-grown individuals with futed organizations might be unable to
adapt themselves to new conditions. Therefore, generation exists “to
adapt and alter the race to changing world.” l9 Darwin’s theory of
generation, which has been ably discussed by David Kohnzo is much
too complex to go into here, but its essential character may be simply
enough stated. A change in the conditions under which an organism
lives affects its reproductive system, causing it to produce varying
offspring. These variations differ from their parents in ways that
serve to adapt them to the new circumstances; that is, the generative
system automatically produces offspring that are adapted to the changed
conditions.*l This remained Darwin’s view throughout the pre-Malthus
period. A second major part of Darwin’s solution, introduced in the C
notebook, is the notion that environmental changes induce changes in
habits, and these in turn cause changes in structure.22 This Lamarckian
theory is in one fundamental respect similar to Darwin’s theory of
generation: both theories postulate an automatic organic response to
changes in inorganic conditions. They describe mechanisms by which
nature provides that geological change does not disrupt the adaptation
18. B, p. 2. “Why is life short, why such high object - generation.”
19. B, pp. 2-4 (Darwin’s
emphasis).
20. “Path to Natural
Selection,”
pp. 52-61, 90-135.
21. This character
of Darwin’s
theory
of generation
was noted by Gruber
in
the B notebook,
but he concluded
that it had disappeared
before Darwin
read
Malthus;
Darwin
on Man, p. 157. See, however,
C, p. 236, D, pp. 166-167,
and
D, p. 175, where Darwin
seems to restate his early views.
22. See especially
C, pp. 51, 62-63,
124, 163, 171-173,
199 and D, p. 107.
Although
this appears to be scarcely
compatible
with Darwin’s
theory
of adaptation by generation,
Darwin
treated
his two theories
as complementary;
see D,
pp. 174e-177.
Sandra Herbert
and David Kohn have both emphasized
Darwin’s
adoption
of Lamarckian
views in 1838; Herbert,
“Man,
Part II,” p. 204; Kohn,
“Path to Natural
Selection,”
pp. 126-l 32.
216
Darwin after Malthus
of the organic to the inorganic world.23 In this, both reflect Darwin’s
commitment to the harmonious view.
From this too-brief glance at Darwin’s early speculations we can see
that the idea of harmony furnished not only the final cause of transmutation, but also the framework and constraints within which Darwin’s
mechanisms operated. Transmutation here is not constant and ubiquitous change. It occurs only in response to environmental change, which,
by causing organisms to be less well adapted, triggers the production of
new, well adapted forms. It is this pattern and this limited action of the
mechanism for change that we find carried over into the post-Malthus
period.
“THE FINAL CAUSE OF ALL THIS WEDGING”
The notebook passages in which Darwin recorded his new insight
upon reading Malthus so obviously contain the basic elements of the
theory of natural selection that we are prone to see in them virtually
the whole of Darwin’s mature theory, with its emphasis on chance,
struggle, and imperfection. But if we read these passages not from the
perspective of 1859, but from that of 1838, they appear in a different
light. The sentence in which the new theory is announced is itself an
unambiguous reiteration of the harmonious view of nature. After
describing the “warring of the species” that must result from the pressure of population, Darwin wrote, “The final cause of all this wedging,
must be to sort out proper structure, & adapt it to changes, - to do
that for form, which Malthus shows is the find effect (by means however of volition) of this populousness on the energy of man.“24 This
passage points directly to the hopeful, or harmonious, interpretation of
the principle of population that was common to Malthus and to the
natural theologians of Darwin’s day. Darwin had already encountered
several varieties of this interpretation elsewhere. He found it, for
instance, in Paley’s Natural 7heoZogy, and in William Kirby’s Bridgewater Treatise, in each of which it took a somewhat different form.25
Its principal element in Malthus’s Essay is the proposition that superfecundity promotes useful human activity.
23. The preservation
of harmony
was not, of course,
the only function
of
these mechanisms.
Darwin
wanted
to believe,
for instance,
that the generative
process operated
in such a way as to assure organic progress
and, ultimately,
the
production
of man; see D, pp. 49, 57-58.
24. D, pp. 134-135e
(my italics).
25. William
Paley, Natural
Theology,
ed. Charles
Bell and Lord Brougham,
217
DOV
OSPOVAT
Malthus is remembered chiefly for his pessimism. But he, like most
of the political economists of his school, supposed that society runs
according to divinely appointed laws, which laws must, therefore, be on
the whole good. The enunciator of such laws frequently chose not
merely to explain their operation, but to show how they fit into the
established order of things - or, what is their final cause. In the case of
a law such as the principle of population, which could be seen to have
unpleasant effects, it was further necessary to explain how this partial
evil was conducive to universal good. This was especially important for
Malthus, who aimed to persuade the poor by such an argument that
riotous behavior and insubordination could not improve their condition.26 In the first edition of his Essay Malthus devoted the two concluding chapters to natural theological reasoning on his principle, an
attempt, as he put it, to give a view of the situation of man on earth
that is consistent with our ideas of the “power, goodness, and foreknowledge of the Diety.“*’ In subsequent editions these chapters were
dropped and the natural theology distributed into several other parts of
the Essay. The bulk of it came to rest in Book IV. There Malthus
argued that the human activity that produces all the advantages and
improvements of civilized life is the result of the powerful and universal
desire for food, clothing, houses, and so forth. But this desire alone is
an insufficient stimulus to elicit the sort of actions that the creator’s
purposes require:
The desire of the means of subsistence would be comparatively
confined in its effects, and would fail of producing that general
2 ~01s. (New York:
Harper
and Bros.,
1839),
11, 138-139,
147-156;
William
Kirby,
On the Power,
Wisdom,
and Goodness
of God, as Manifested
in the Creation of Animals,
and in Their History,
Habits,
and Instincts,
rev. ed. by T. R.
Jones,
2 ~01s. (London:
H. G. Bohn,
1853),
I, 157-159
(Darwin
read Kirby
during the periodin
which he kept the B notebook;B,
p. 141). John Bird Sumner,
A Treatise
on the Records
of the Creation
and on the Moral Attributes
of the
Creator,
6th ed. (London:
J. Hatchard
and Son, 1850), pp. 214-275,
also includes
a discussion
harmonizing
Malthus
and natural theology.
Darwin
read his Evidence
of Christianity
(see Gruber,
Darwin
on Man, pp. 125-I 26) and may have known
his Treatise
(first
edition,
1816).
On the hopeful
interpretation
of Malthus,
see Robert
Young.
“Malthus
and the Evolutionists:
The Common
Context
of
Biological
and Social Theory,“Past
andpresent
no. 43 (May 1969), 109-145.
26. Thomas
Robert
Malthus,
An Essay on the Principle
of Population:
or a
View of Its Past and Present
Effects
on Human
Happiness,
3rd ed., 2 ~01s. (London: J. Johnson,
1806), II, 498499.
27. Thomas
Robert
Malthus,
An Essay on the Principle
of Population
(1st
ed.), ed. Philip Appleman
(New York: W. W. Norton,
1976), p. 116.
218
Darwin after Malthus
activity so necessary to the improvement of the human faculties,
were it not for the strong and universal effort of population to
increase with greater rapidity than its supplies. If these two tendencies were exactly balanced, I do not see what motive there would be
sufficiently strong to overcome the acknowledged indolence of man,
and make him proceed in the cultivation of the ~oil.*~
This is clearly the discussion to which Darwin was referring when he
wrote that population pressure in nature would “do that for form,
which Malthus shows is the final effect . . . of this populousness on the
energy of man.” For Malthus, the potential increase of population
beyond the means of subsistence produces that human activity which is
required to accomplish the creator’s aims. For Darwin, similarly, the
final cause of populousness is the production of that constant adaptation of organisms to conditions which he believed to be characteristic
of “this perfect world.“29
Influenced by the Darwin of the Origin of Species, we have grown
accustomed to think of natural selection as necessarily implying a
universe of imperfection and disharmony. It may have been this assumption that led Camille Limoges to argue that Darwin’s crucial step
in constructing the theory of natural selection was the dismantling of
the traditional conception of the economy of nature. This was accomplished, he argued, before Darwin’s reading of Malthus, that event merely serving to bring together the various elements of Darwins’s theory.30
David Kohn, who recognized that until he read Malthus Darwin saw
nature as a harmonious system, identified the destruction of that
conception as Malthus’s principal contribution to natural selection.31
But in fact there is in Darwin’s notebook entries for September 28
1838, no suggestion that he then ceased to believe in a “system of
great harmony.” Instead, we find a direct analogy drawn between
Darwin’s new theory and those arguments that Malthus used to incorporate the principle of population into that very system.
For a month or two after he read Malthus Darwin continued to
believe in a “perfect world,” whose changes, both inorganic and organic,
28. Malthus, Essay, 3rd ed., II, 315-316.
29. The quoted phrase is from E, p. 48.
30. Limoges, Sdlection
nafurelle,
pp. 77-80. Limoges did not distinguish
between the two main varieties of perfect adaptation. He saw that Darwin abandoned the Paley-Bridgewater variety and took this to mean that Darwin gave up
the harmonious view.
31. Kohn, “Path to Natural Selection,” pp. v, 144.
219
DOV OSPOVAT
“ALL PARTS OF THE GREAT SYSTEM.“32 A comment on man
from this period suggests that, as was true before he read Malthus,
Darwin meant by “system” all of the laws, extending down to the
lowest level, by which the creator achieved his purposes, including the
existence of man. Man, he said, “is one great object for which the world
was brought into present state.” The “law of transmutation” and the
separation of sexes are means by which the creator has realized this
object - which is to say that Darwin believed still that the ends were
known before the system of laws was established.33 These same months,
however, were the period when Darwin, according to his journal,
“thought much upon religion.“34 He began to doubt whether he
should “talk of Final causes.“35 And he concluded, presumably as a
result of reflecting on the implications of natural selection, that the
details of the system were the result of chance. The production of an
intellectual being was perhaps inevitable, he said, but “what a chance it
has been . . . that has made a man.“36 If it is chance that made man, he
could hardly be considered a final cause of the laws of change. In a
general way, Darwin continued to hold to the hopeful view of things
even in the 1850s. The theodicy of the Origin is essentially the theodicy
of Malthus: “From the war of nature, from famine and death, the most
exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows.“37 But in the fall of 1838
Darwin seems to have come to believe that natural selection could not
be reconciled with the supposition that the effects of particular laws
are
32. E, p. 48; Darwin MSS, vol. 71, fois. 53-58, Cambridge
University
Library (these reading
notes, transcribed
by Paul Barrett,
are published
as “Essay
on
Theology
and Natural
Selection”
in Gruber, Darwin
on Man, pp. 416420).
33. E, pp. 49-51.
34. Gavin de Beer, ed., “Darwin’s
Journal,”
Bull. Brit. Mus. (Nat. Hist.), Hist.
Ser., 2 (1959),8.
35. Darwin
MSS, vol. 71, fol. 58, Cambridge
University
Library
(Gruber,
Darwin
on Man, p. 4 19).
36. E, p. 68. Sandra Herbert
(“Man, Part II,” p. 200) saysthat B, pp. 214215, indicates
that Darwin
at this time believed already that man “was accidental
in his particulars.”
I do not think B, pp. 214-215,
implies this; and E, pp. 48-49,
I think, clearly implies the contrary.
37. Darwin,
Origin,
p. 490. I see no reason to doubt,
and several to credit,
Darwin’s
statement
in the Autobiography
that at the time he wrote the Origin he
believed
in “a First Cause having an intelligent
mind in some degree analogous
to
that of man” and that this cause, not “blind
chance or necessity,”
was responsible
for “this
immense
and wonderful
universe”;
he deserved,
Darwin
said, “to be
called a Theist.”
Nora Barlow,
ed., The Autobiography
of Charles Darwin, 18091882 (New York:
W. W. Norton,
1958), pp. 92-93.
220
Darwin after Malthus
could have been precisely known beforehand. From that point on, he
held that the creator established “only general laws.” 38
THE PERSISTENCE OF PERFECTION
Although Darwin gave up the idea that the details of the world were
part of an original plan of creation, he did not for a long time seriously
question one of the main assumptions of this conception of nature. In
1844 he continued to believe in perfect adaptation rather than the
relative adaptation we find in the Origin of Species. There are several
strands of evidence that may be drawn on to support this claim. Two
are fairly straightforward but, though suggestive, are ultimately inconclusive. A third is more complex and more decisive.
First, there is the fact that Darwin on numerous occasions in the
“Essay of 1844” indicated that he considered perfect adaptation to be
the norm in nature. Unless there is some change in external conditions
to disrupt adaptation, organisms are perfectly suited for the situation
in which they live. Geological changes, he said, result in organisms’
ceasing to be “so perfectly adapted . . . as they orginally were.“39
When an island is in process of formation and some plants or animals by
chance arrive there, “it is impossible that the first few transported
organisms could be perfectly adapted” to all the stations on the new
island; “and it will be a chance if those successivelytransported will be
so adapted. The greater number would probably come from the lowlands of the nearest country; and not even all these would be perfectly
adapted to the new islet whilst it continued low and exposed to coast
influences.“40 And again, while an archipelago is forming, its stations
will not at first be occupied “by perfectly adapted species.“41 In all
these instances perfect adaptation is treated as what is to be expected
except when conditions are altered.
There are, I should point out, other places in the “Essay” in which
Darwin seems to deny perfect adaptation. In reading these, however, it
is necessary to keep in mind the distinction between the teleologists’
conception of perfect adaptation and the idea of limited perfection that
38. F. Darwin,
39. Ibid.,
1844,
“Essay
of 1844,”
seems that this may
40. Ibid., 1844,
41. Ibid., 1844,
ed., Foundations,
1844, p. 134.
p. 91, Most of the argument
in this section
is based on the
but examples
are drawn
from the “Sketch
of 1842”
when it
make Darwin’s
position
clearer.
p. 185.
p. 196.
221
DOV OSPOVAT
Darwin, Owen, and others espoused.42 To the teleologists, a perfectly
adapted form was the best possible form for the conditions under
which it lived. Antiteleologists, however, held that the perfection of
organisms was limited by certain general laws, such as the law of
adherence to a common type, or, in Darwin’s case, the laws of heredity.
The idea of limited perfection is nicely expressed in some of Darwin’s
early post-Malthus notes: “I look at every adaptation, as the surviving
one of ten thousand trials. - each step being perfect - or nearly so
(except in isld) although having hereditary superfluities, Man could
exist without mammae - to the then existing conditions.“43 Perfection
here is limited by the “hereditary superfluities.” In the pre-Malthus
notebooks Darwin constantly argued against the teleologists’ explanations, and he continued to do so in the “Essay of 1844.” It is in this
context alone that Darwin denied perfect adaptation, and it is the
teleological concept of perfection that he denied. For instance, in
discussing geographical distribution, Darwin was concerned to show
that it could not be explained simply by the adaptation of organisms
to external conditions. To prove the teleological explanation inadequate, he cited the case of introduced forms that compete successfully
against the native inhabitants:
I
Although every species is admirably adapted (but not necessarily
better adapted than every other species, as we have seen in the great
increase of introduced species) to the country and station it frequents;
yet it has been shown that the entire difference between the species
in distant countries cannot possibly be explained by the difference
of the physical conditions of these countries.44
This was a telling blow against the teleologists’ version of perfection,
but it left untouched Darwin’s own: that within the limits imposed by
the laws of heredity and the accidents of transportal, the native inhabitants are perfectly adapted. In Darwin’s theory of 1844 the natives
cannot be further improved, for, being perfectly adapted, they do not
vary. Only if some change in conditions causes them to be no longer
perfectly adapted will natural selection begin to work.
How far Darwin still was in 1844 from the idea that species are only
42. Seethe discussionabove.
43. Darwin MSS, vol. 71, fol. 58, Cambridge University Library (Gruber,
Darwin
on Man, p. 420.
44. F. Darwin, ed., Foundalions, 1844, p. 171; see also pp. 153-154, and
1842, p. 33n.
222
Darwin after Malthus
relatively well adapted, in comparison with their competitors, can be
seen by contrasting his conclusions on introduced forms in the “Essay”
with those he drew in the Origin ofSpecies. In 1844 he said, “I mean
by not being perfectly adapted, only that some few other organisms can
generally be found better adapted to the country than some of the
aborigines.” 45 In the Origin he added, significantly, “we may safely
conclude that the natives might have been modified with advantage, so
as to have better resisted such intruders.“% In 1859 Darwin interpreted
the phenomenon to mean that the natives were not perfectly adapted in
any meaningful sense. There is always room for improvement. In 1844
it meant only that the teleologists’ principle of adaptation was untenable, thus leaving the door open for Darwin’s rival explanation in
terms of transmutation and transportal.
A second, similar strand of evidence comes from Darwin’s description
of the products of natural selection. “My theory,” he wrote, shortly
after reading Malthus, “makes all organic beings perfectly adapted to all
situations where in accordance to certain laws they can live.“47 The
fullest discussion of the results of natural selection is in Darwin’s
comparison of man’s selection with nature’s. This is a topic that first
appeared in the E notebook in December 1838. “If nature . . . had the
picking,” she could make a webbed-footed dog “far more easily than
man.rr48 Domestic races, Darwin said, “are made by precisely same
means as species - but latter far more perfectly & infinitely slower.”
No domestic animal, however, “is perfectly adapted,” he said, implying
that natural species are.49 In the “Essay of 1844” Darwin contrasted
the imperfection of man’s techniques with the operation of the “natural law of selection.” Man, he said, selects chiefly by eye and cannot
see whether the internal structure is well suited to the external. Nor can
he detect shades of constitutional differences. He has bad judgment and
he is capricious: he and his successorsdo not select for the same end for
hundreds of generations. Man selects forms that are useful to him rather
than those that are best adapted to the conditions under which they
live. And he does not keep those conditions uniform. Frequently he is
unwilling to destroy an animal which is not up to his standard. And he
45.
46.
47.
L&win
48.
49.
Ibid., 1844, p. 153.
Darwin,
Origin,
p. 83.
Darwin
MSS, vol. 71, fols.
on Man, p. 417).
E, p. 63.
E, p. 71; see also p. 75.
53-58,
Cambridge
University
Library
(Gruber,
223
DOV
OSPOVAT
often begins selecting with a sport that departs considerably from the
parent form.
Nature, by contrast, selects varieties that differ only slightly from
the parent forms. Conditions are constant for long periods and change
only slowly. Crossing rarely occurs. Nature never fails to destroy forms
that are not well adapted and never selects forms unless they are better
adapted than their parents. Nature’s selection is not capricious, but
goes on steadily for thousands of years adapting the form to the same
conditions. The selecting power works on internal structures as well as
external, testing the whole organism during its whole life, and if it
proves to be less well adapted than its congeners it is inevitably destroyed. “Every part of its structure is thus scrutinised and proved good
towards the place in nature which it occupies.” It follows that nature’s
productions will be far more perfect than man’s. In domesticated
animals, selection for the same ends, steadily, for a number of generations, under suitable conditions, and without crossing, produces forms
that are “true,” or subject to little variation. Nature’s forms must be
incomparably “truer,” for they have been made by rigid and steady
selection, without crossing, continued for thousands of years. The result
is forms “excellently trained and perfectly adapted” to conditions.
Such forms seldom vary, which Darwin believed to be one sure mark of
a species.50
If not carefully examined, Darwin’s description of the process by
which these perfectly adapted forms are produced might lead one to
think that in 1844 he inconsistently believed at the same time in both
perfect and relative adaptation. But this is not the case. When geological
changes alter the conditions under which a species lives, or when individuals of a species are transported to a new region, the reproductive
system is affected, and the species begins to vary. “Almost every part of
the body,” he said, “would tend to vary from the typical form in slight
degrees, and in no determinate way.” 51 The variations, that is, are not
automatically adaptive, as he had formerly assumed. Some variant
individuals will be better adapted than others to the new conditions,
and they will have a better chance of survival. Here Darwin clearly is
saying that there are differences in adaptedness; some organisms are
better adapted, others “less well adapted.“52 But it is important to
note that he is not speaking of species. Some variant individuals that
50.
51.
52.
224
F. Darwin,
ed., Foundations,
Ibid., 1844, p. 85.
Ibid., 1844, p. 95.
1844,
pp. 94-96.
Darwin after Malthus
occur under changed conditions will be better adapted than others and
than the parent form, which, as a result of the change, ceases to be
perfect. But species, the stable, true-breeding end products of selection,
are perfectly, not relatively, adapted.53
Considered in isolation, all of the instances in which Darwin described
adaptation as perfect would be of little moment, for one can easily
imagine that he might have continued to use the term after he had
abandoned the concept. 54 More revealing is evidence derived from the
structure of Darwin’s theory in the “Essay of 1844,” from which it
appears that perfect adaptation, far from being an empty phrase, was
an assumption that governed how Darwin would understand the working of natural selection. The channel through which the assumption
of perfect adaptation exerted its influence was Darwin’s theory of
variation. This was but a slight modification of his pre-Malthus theory
of generation. In the first three transmutation notebooks, Darwin
suggested that external changes would destroy adaptation if they were
not accompanied by corresponding organic changes. The balance was
preserved, he thought, because external changes, by affecting the
reproductive systems of organisms, cause them to produce offspring
that are adapted to the new conditions. After he adopted the theory of
natural selection, Darwin supposed that the generative process produces
not new adaptations, but merely variations, on which natural selection
works. But he continued to believe that offspring unlike their parents
are produced only when the reproductive system has been influenced
by external changes. This was his explanation of both variation under
domestication and variation under nature in his two essaysof the 1840s.
Under certain conditions, he said, speaking of domestication, organisms
are altered during their individual lives, and these alterations may be
passed on to future generations. Habits of body and mind, structural
changes resulting from use and disuse of organs, effects of food, climate,
and occupational diseases, and the tendency to contract some diseases
may all be inherited. But these variations from the direct effect of
conditions on individuals are “extremely rare compared with those
which are congenital or which appear soon after birth.” These latter
are “infinitely numerous,” and it is chiefly on them that the breeder
53.
ferences
Ibid., where,
at the top of the page, Darwin
assumes that there are difin the adaptednessof variant forms, while at the bottom
of the page he
assertsthat the speciesproduced by natural selectionare perfectly adapted.
54. The language of perfect adaptation does in fact occasionallycrop up in
the Origin and later works.
225
DOV
OSPOVAT
works in order to make new races.55 The cause of these “congenital”
variations, Darwin said, is “the accumulated effects of a change of all
or some of the natural conditions of the life of the species.” 56 The
indirect effect of these changes on the reproductive system causes the
organization of the embryo to become “in a slight degree plastic,” and
variations are produced.57
This same cause Darwin believed must also produce variation in
nature: “Domestication seems to resolve itself into a change from the
natural conditions of the species . . . if this be so, organisms in a state of
nature must occasionally, in the course of ages,be exposed to analogous
influences; for geology clearly shows that many places must, in the
course of time, become exposed to the widest range of climatic and
other influences.” 58 The slow changes from geological causes probably
act on the reproductive organs during several generations before the
accumulated effects cause the species to vary. Sometimes, however, a
catastrophic geological change - “as when an isthmus at last separates”
- or the dissemination of seeds into a new region will suddenly bring an
organism into contact with new conditions and thus produce a tendency
to vary.59 “The reproductive system would be affected, as under
domesticity, and the struct&e of the offspring rendered in some degree
plastic”; or, as he said in 1842, “the mould in which they are cast”
would vary slightly. 6o The hereditary type, or “mould,” fixed and
stabilized by the long-continued process of generation, would cease,
under altered conditions, to govern rigidly the form of new individuals.
This theory of variation, carried over with little change from Darwin’s
pre-Malthus period, had two important consequences for the theory
of natural selection. One is that it sharply limited the availability of
materials on which natural selection might work. Geological conditions
remain the same for long periods of time.61 And geological change is
slow, so that only after a long time will its accumulated effects cause a
55. F. Darwin,
ed., Foundations, 1844, pp. 57-59.
56. Ibid., 1844, pp. 77-78.
57. Ibid., 1844, pp. 62-63.
58. Ibid., 1844, p. 83 (Darwin’s
emphasis).
59. Ibid., 1844, p. 84; see also 1842, pp. 4-5.
60. Ibid., 1844, p. 85; 1842, p. 5. Darwin
supposed
that even in the absence
of significant
external
change individuals
of a species might not always be exactly
alike. But he thought
they would vary chiefly
in the “external
and less important
parts”;
and for obvious
reasons he did not base his theory
on these differences.
Under
changed
conditions,
however,
even the most essential
parts of a plant’s or
animal’s organization
might vary (ibid., 1844, pp. 82-83, 85).
61. Ibid., 1844, p. 95.
226
Darwin after Malthus
species to vary. Therefore, there can be very little variation among
organisms in a state of nature. This Darwin stated again and again in the
two essays of the 1840s: “Wild animals vary exceedingly little”;62 “the
proverbial expression that no two animals or plants are born absolutely
alike, is much truer when applied to those under domestication, than to
those in a state of nature”$j3 “ most organic beings in a state of nature
vary exceedingly little “;@ “the amount of variation [is] exceedingly
small in most organic beings in a state of nature, and probably quite
wanting (as far as our sensesserve) in the majority of cases.“65 This conclusion followed directly from Darwin’s belief that in the absence of
external change organisms are perfectly adapted and so do not vary.66
The second consequence, closely related to the first, is that transmutation can occur only in those rare situations in which there is a change
in conditions. At all other times population pressure merely operates to
weed out misfits. This is not explicitly stated in the “Essay of 1844.”
But in both the “Essay” and the “Sketch of 1842”, whenever he
discussed variation or gave illustrations of the working of natural
selection, Darwin stipulated that there is a change in conditions.67 At
the end of the “Sketch” he went so far as to leave himself a note on the
need to include a discussion from Lyell, or a reference to him, “to show
that external conditions do vary” - a fact that virtually every geologist
and naturalist in Darwin’s day fully admitted.@
62.
63.
64.
Ibid.,
1842,
p. 4.
Ibid., 1844, p. 59.
Ibid, 1844, p. 81.
65. Ibid., 1844, p. 83.
66. In one respect - the key role of external
change - Darwin’s
view of variaresembled
closely
the traditional
idea that each species was endowed
with
some capacity
to adapt to changes in its environment;
that is, that its form was
modified
in response
to alterations
in external
conditions.
This was Lyell’s view;
Principles of Geology,
5th ed., 2 ~01s. (Philadelphia:
James Kay Jun. and Brother,
1837), I, 506-515
(Book III, chap. Ill).
67. F. Darwin, Foundations, 1842, pp. l-2,4-5,
8-9,13-15
(Darwin
considered
crossing to be the equivalent
of a change in conditions),
20, 21,30-31,
32-33, 34n,
37; 1844, pp. 57-76, 83,84-85,90-92,
110, 120, 122,145,
153-154,
183-194.
68. Ibid.,
1842, p. 53. In Chapter
II of the “Essay”
Darwin
indicated
most
clearly
his view of the difference
between
the situation
in which conditions
are
changing
and that in which they remain the same. Population
pressureoperates
continually
to produce
struggle in nature. But with “external
conditions
remaining
the same,”
the result
of the struggle
is stability:
each individual
of each species
merely
“holds
its place.”
However,
when “external
conditions
. . change,” the
original inhabitants
cease to be perfectly
adapted;
the change causes variation;
and
selection
favors
the variant
forms that are better adapted
to the new conditions
(ibid., pp. 90-91).
tion
227
DOV
OSPOVAT
Francis Darwin long ago called attention to differences between the
“Essay of 1844” and the Origin of Species on the questions of the
amount of variation in nature and the need for external change to
induce variation. The latter contrast was noted by Huxley, too.69 But
neither had any inkling of the explanation of the differences, which is
simply that in 18.59 Darwin no longer believed in perfect adaptation. In
the Origin Darwin said that there was much variability in nature, and he
supposed that no change in conditions is necessary for variation and
transmutation to occur.7o In 1844 he believed that there is little variation and that changes in conditions are necessary; and this was because
in 1844 he still believed that in the absence of change organisms are
perfectly adapted. In essence, the effect of change on the reproductive
system was, for Darwin, the effect of the organism’s no longer being
perfectly adapted. Perfectly adapted organisms have no need to change,
and so they do not vary. A passage from the E notebook, written in
March 1839, says exactly this: “In the place where any species is most
common, we need not look for change, because its numbers show it is
perfectly adapted.” ” Seven years later Darwin’s opinion remained
unaltered. A note dated “July [18]46” reads: “When new form introduced into island, it must not be perfectly adapted, else it will not
vary.” 72
Darwin’s persistent belief in perfect adaptation dictated that the
structure of his theory of transmutation in 1844 would be essentially
the same as in the pre-Malthus notebooks. In the period of his early
speculations, the purpose of transmutation was to preserve the harmonious adaptation of organisms to their environments. When external
change threatened this adaptation, a natural mechanism was automatically called into play to maintain or restore it. The same pattern of
69. Ibid., pp. xxviii-xxix;
1844, p. 81n.
70. Darwin,
Origin,
pp. 45, 82-83,
113. See also Darwin’s
letter to Asa Gray
presented
to the Linnean
Society
in 1858 (Gavin
de Beer, ed., Evolurion
by
Nufurul
Sekcrion
[Cambridge:
Cambridge
University
Press, 19581, p. 265). This
did not mean that Darwin
no longer thought
it necessary
to explain
variation
or
thought
that variation
was inherent
in the generative
process; it meant merely
that
the causes of variation
might be more subtle and more varied than he had formerly
allowed
- that is, variations
did not occur only when a form ceased to be “so
perfectly
adapted”
as it had been.
71.. E, p. 122e. In another
passage the correlation
between
less-than-perfect
adaptation
and variability
is drawn explicitly:
“No domesticated
animal is perfectly adapted
to external
conditions.
- (hence
great variation
in each birth)”
(E,
p. 71).
72. Darwin
MSS, vol. 16ii, fol. 303, Cambridge
University
Library.
228
Darwin after Malthus
change characterizes the “Essay of 1844.” Before Malthus, Darwin’s
mechanisms were the generation of new adaptations and the effect of
changed habits. In the “Essay of 1844,” changes in conditions bring
variation and natural selection into play. In both cases, the result is
the same - the production of new, perfectly adapted forms.
There can be no question that natural selection was a decisive
breakthrough in Darwin’s theorizing about transmutation. It gave him a
new and better mechanism than any he had considered previously for
explaining change and adaptation in the organic world. Yet when
Darwin’s intellectual progress is viewed from another angle it is evident
that there is an underlying continuity in his thought, stretching from
the opening pages of his first transmutation notebook, across the
Malthusian divide, to beyond the “Essay of 1844”: Malthus and natural
selection did not at once succeed in altering the natural theological
structure of Darwin’s earliest theories;his new mechanism was mounted,
so to speak, in an old housing.
FROM 1844 TO 1859
The idea of relative adaptation in the Origin is perhaps the best
indication of the extent to which Darwin’s views had by 1859 diverged
from those of his fellow naturalists.73 By the same token, the idea of
perfect adaptation in the essays of the 1840s is a fair measure of the
extent to which Darwin’s views then still reflected the natural theological perspective of most of his contemporaries, the perspective which
Darwin brought to the problem of organic change when he opened his
first notebook in 1837. One very obvious implication of this is that in
1844 Darwin still had a long way to go before arriving at the position he
adopted in the Origin of Species. I will not try to indicate what considerations finally led Darwin to the views we find in the Origin, except
to say that I believe one crucial change was his abandoning at last the
idea of perfect adaptation. By this I do not mean to imply that there
was some single instant between 1844 and 1859 at which a clear break
occurred. There is continuity in the development of Darwin’s theory
after, as well as before, 1844. For instance, it was, I believe, at just the
period when Darwin was moving toward the concept of relative adaptation that he wrote, “By Nature I mean the laws ordained by God to
govern the Universe. “74 From this and other aspects of his theory of
73. Except
Wallace.
74. Robert
Stauffer,
ed., Charles
Darwin’s
Cambridge
University
Press, 1975), p. 224.
Natural
Selection
(Cambridge:
229
DOV OSPOVAT
the 185Os, it appears that Darwin had not completely relinquished the
conception of nature that we find in the early notebooks. But his
speculations after 1844 gradually produced a new understanding of
adaptation that had the effect of freeing natural selection, to a considerable degree, from the constraints I have described.
This much said, it may be useful in conclusion to state in summary
form some of the contrasts that reveal the distance that separates the
Origin and the two essays of the 1840s. In 1844 Darwin believed that
there is “exceedingly little” variation in nature; in 1859 he said that
variation is common. In the “Sketch” he suggested that there is a
common “mould” for all the members of a species; in 1859 he said,
“No one supposes that all the individuals of the same species are cast in
the very same mould.“75 In the “Essay” he believed that changes in
external conditions were necessary to produce variation and transmutation; in the Origin he believed no change was necessary. In 1844 he
supposed that transmutation would probably occur “only rarely” and
“in some few districts:’ m
. the Origin he thought there was no country
in which it might not be going on even now.76 In 1844 he believed in
perfect adaptation; by 1859 he believed that “organic beings seem to
be perfect only in that degree required by our theory, namely to be
enabled to struggle with all competitors in their native country.“77 This
last contrast, I believe, is the fundamental one, for in it lies a large part
of the explanation of all the others.
Acknowledgments
I am deeply indebted to David Kohn, without whose dissertation and
conversation I would never have undertaken a serious examination of the
development of Darwin’s theory; and to Sydney Smith, who introduced
me to the Darwin collection at Cambridge University Library and has assisted me in numerous ways since then. My thanks are due also to all who
participated in the discussion of this paper at the meeting of the History
of Science Society at Madison, Wisconsin, in October 1978. Part of the
research for the paper was conducted with the help of a Maude Hammond Fling summer research fellowship from the University of Nebraska.
75. Darwin, Origin, p. 45. The alteration in Darwin’s view on this point was
due at least in part to his work on barnacles; Francis Darwin, ed., Life and Letters
of Charles
Darwin,
2
~01s.(New York: D. Appleton, 1888), I, 397.
76. Darwin, Origin, pp. 82-83.
77. The quotation is from Natural
Selection,
102, for the same idea less clearly expressed.
230
p. 386; see Origin, pp. 82-83,