1. Louis Agassiz
1807 - 1873

2. 1906

3. Louis Agassiz
Educated in Zürich,
Heidelberg and Münich
Influence of Cuvier, von
Humbolt, & Oken
Ph.D. (1829) + M.D. (1830)
Fishes of Brazil (1829)
Poissons Fossiles (1833 - ’43)
Professor of natural history
at Lyceum at Neuchâtel

4. “Study on Glaciers”
1840

5. Louis Agassiz
1846 - Lecture series at
Lowell Institute
“The Plan of Creation as
Shown in the Animal
Kingdom”
1847 - Professor at
Lawrence Scientific School
of Harvard University
1859 - Museum of
Comparative Zoology

6. 1855
Contributions to the Natural
History of the United States
Greeted with “a stunning
silence”

7. Contributions
1) Essay on Classification
2) North American Testudinata
3) Embryology of the Turtle

8. Essay on Classification
1859
Support from Owen and
Sedgwick
History of systems of
classification
Accepted Cuverian
embranchements
Idealistic definitions of
biological categories that
were useless.

10. On the Essay
“The results are so practical that
even my students of one years
standing with the rules are able
to trace for themselves … the
natural limits of genera and
families and they actually do it
better than our old practiced
Zoologists. So you see it will tell
in the progress of science.”
Letter to Spencer F. Baird

11. Darwin on Species
“I look at the term species, as one
arbitrarily given for the sake of
convenience to a set of
individuals closely resembling each
other, and that it does not
essentially differ from the term
variety, which is given to less distinct
and more fluctuating forms. The
term variety, again, in comparison
with mere individual differences, is
also applied arbitrarily, and for
mere convenience’ sake.”

12. Agassiz on Species
“Polygenism”
Species were real, fixed, unchanging
entities found as ideas in the mind of
God
Large numbers of each species were
created in their intended habitat
after catastrophes
The (instantaneous) Ice Age
presented a last barrier between the
“prophetic” species and modern
fauna
No genetic connection between
fossil and modern species

13. Natural Theology
“We recognize intelligence in
the construction of a machine
because we know that it could
not operate in the manner it
does were it not the device of
an intelligent artisan … The
animal kingdom especially has
been constructed upon a plan
which presupposes the
existence of an intelligent
being as its Author”

14. Natural Theology
Nature shows “not only thought,
it shows also premeditation,
power, wisdom, greatness,
prescience, omniscience,
providence. In one word, all these
facts in their natural connection
proclaim aloud the One God,
whom man may know, adore and
love; and Natural History must in
good time become the analysis of
the thoughts of the Creator of
the Universe.”

15. Chauncey Wright
Origin rendered “Agassiz’s
essay on classification a
useless and mistaken
speculation; creation is a word
pretending knowledge and
feigning reverence.”

16. Creationist?
“I dread quite as much the exaggeration of
religious fanaticism, borrowing fragments of
science, imperfectly, or not at all,
understood, and then making use of them
to prescribe to scientific men what they are
allowed to see or find in nature” (Letter to
Sedgwick, 1845).
Nature not Scripture should be taken
literally, and interpolations were not to be
allowed
Lectured on “the absurdity” of Adam & Eve.
Genesis recounted the experiences of the
White race only and describes localized
events.

17. Shared Data –
Different Interpretations
The “facts upon which
Darwin, Wallace, Haeckel
and others base their views
are in the possession of
every well-educated
naturalist. It is only a
question of interpretation,
not of discovery of new
and unlooked-for
information” (1874)

18. On Origin
“Ingenious but fanciful” (Boston
Natural History Society, 1860)
“species are based upon relations
and proportions that exclude … the
idea of common descent” (American
Journal of Science & Art, 1860)
“a scientific mistake, untrue in its
facts, unscientific in its method, and
mischievous in its tendency” (op cit.,
1860)

19. French (1869) Edition of Essay
Darwinists put philosophy before facts
“Darwinism excludes nearly all the mass of acquired
information, for it assimilates and takes exclusively that which
could be useful to the Doctrine. It is not the facts that
determine for the Darwinists the nature of their
generalizations, it is the system that dictates the nature of
their reality.”
Variation has distinct limits
Fossil record does not support Darwinian expectations
“I would have been a great fellow for evolution if it had not
been for the breaks in the paleontological record”

20. 1874
“The most advanced Darwinians seem
reluctant to acknowledge the
intervention of an intellectual
power in the diversity which obtains in
nature, under the plea that such an
admission implies distinct creative acts for
every species, What of it, if it were true?
Have those who object to repeated acts
of creation ever considered that no
progress can be made in knowledge
without repeated acts of thinking? And
what are thoughts but specific acts of the
mind? Why should it then be unscientific to
infer that the facts of nature are the result of
a similar process, since there is no evidence
for any other cause?”

22. Legacy
Paleo-icthyological studies
Taxonomic works
Theory of glaciation
Use of multiple forms of
evidence in classification
Classification without
reference to process (c.f.
modern cladistics)

23. Legacy
Institutions like the
American Association for
the Advancement of
Science (AAAS)
Popularization of natural
history among public
Students
Museum of Comparative
Zoology, Harvard

24. Alphaeus Hyatt
David Starr Jordan
Alexander Agassiz
Joseph LeConte

25. Stephen
Ernst E.O.
Jay
Mayr Wilson
Gould

26. Charles Hodge
“What is Darwinism? It is
Atheism. This does not
mean, as before said, that Mr.
Darwin himself and all who
adopt his views are atheists;
but it means that his theory is
atheistic, that the exclusion
of design from nature is,
as Dr. Gray says, tantamount
to atheism.” (1874)

27. Asa Gray
1810 - 1888

28. Asa Gray
Presbyterian.
Fisher Professor of Natural History,
Harvard University, 1842-1888.
Established systematic botany in the US.
Founded America’s first major herbarium.
Authored a number of popular botanical
works.
President, American Association for the
Advancement of Science, 1871.
Strong ties (via correspondence) with
European botanists & naturalists

29. Hooker
Gray

30. Plant Biogeography Backgammon
Design
Taxonomy
Hermaphrodites
The Abolition of Slavery Beards

31. Darwin to Gray, Sept. 5th 1857

33. Review of Origin
“If Darwin even admits—we will not say adopts—
the theistic view, he may save himself much
needless trouble in the endeavor to account for
the absence of every sort of intermediate form.”
“Wherefore, so long as gradatory, orderly, and
adapted forms in Nature argue design, and at least
while the physical cause of variation is utterly
unknown and mysterious, we should advise Mr.
Darwin to assume, in the philosophy of his
hypothesis that variation has been led along
certain beneficial lines.”
“the accidental element may play its part in Nature
without negativing [sic] design in the theist's view.”
Atlantic Monthly, 1860

34. Design in Nature
“We infer design from certain arrangements and results; and
we have no other way of ascertaining it.”
“The whole argument in natural theology proceeds upon the
ground that the inference for a final cause of the structure of
the hand of the valves in the veins is just as valid now, in
individuals produced through natural generation, as it would
have been in the case of the first man, supernaturally created.”
“Nature must also have been designed, and clinches our
belief, from manifold considerations, that all Nature is a
preconcerted arrangement, a manifested design.”

36. “Natural Selection Not Inconsistent
with Natural Theology”
1861

37. “Natural Selection Not Inconsistent
with Natural Theology”
Argues that Darwin:
1) Had put forward an eminently
scientific theory.
2) Had not written atheistically.
3) Presented no new problems for
Christian belief.
4) And proposed an idea which
substantially enhanced Natural
Theology.

38. Three Theistic Views
“The view of its exertion at the beginning of time,
endowing matter and created things with forces
which do the work and produce the phenomena.”
“This same view, with the theory of insolated
interpositions, or occasional direct action, engrafted
upon it-the view that events and operations in
general go on in virtue simply of forces
communicated at first, but that now and then, the
Deity puts his hand directly to the work.”
“The theory of the immediate, orderly,
and constant, however infinitely
diversified, action of the intelligent
efficient Cause.” (i.e. God is immanent in the
process)

39. Darwin’s Actions
Throughout 1860: Darwin exhibited
nothing but praise and thanks in
reference to Gray’s essays and Reviews.
February 1861: Darwin distributes the
first 100 copies of Gray’s pamphlet,
believing it will do his theory “right good
service.”
March - May 1861: Darwin receives
many letters and personal testimonies
concerning the excellence of Gray’s
pamphlet.

40. Darwin’s Doubts
“I have been led to think more on this
subject of late, & grieve to say that I
come to differ more from you. It is not
that designed variation makes, as it
seems to me, my Deity “Natural
Selection” superfluous; but rather from
studying lately domestic variations
& seeing what an enormous field of
undesigned variability there is
ready for natural selection to
appropriate for any purpose useful to
each creature.”
To Gray, June 1861

41. 1868

42. To Darwin
“I was put on the defense by your
reference to an old hazardous remark
of mine. I found your stone-house
argument unanswerable in substance
(for the notion of design must after all
rest mostly on faith, and on
accumulation of adaptations, &c): so
all I could do was to find a vulnerable
spot in the shaping of it, fire my little
shot, and run away in the smoke.”
1868

43. 1877
“The conception that variation
takes place in definite - or at
least not in indefinite - lines, is
an idea which is ... as inferable
from a good many facts than as
any thing to swear by. I think so
- yet, I am sure to say, it is no
part of Darwinism, pure &
simple.”

44. “Design vs Necessity”
“Judging from the past, it is not improbable
that variation itself may be hereafter
shown to result from physical causes.”
“The discovery of the cause of variation
would be only a resolution of variation
into two factors: one, the immediate
secondary cause of the changes, which so
far explains them; the other an unresolved
or unexplained phenomenon, which will
then stand just where the product,
variation, stands now, only that it will be
one step nearer to the efficient cause.”
1860

45. 1870
“There is of course a cause for the
variation.”
“Nobody supposes that any thing changes
without a cause; and there is no reason
for thinking that proximate causes of
variation may not come to be known”
“Out of this would immediately rise the
question as to what can be the foundation
and beginning of this long and wonderful
chapter of accidents which has produced
and maintained, not only for this time but
through all biological periods, an ever-
varying yet well-adapted cosmos.”

46. Darwiniana
“Natural selection is not the wind which
propels the vessel, but the rudder which,
by friction, now on this side and now on
that, shapes the course. The rudder acts
while the vessel is in motion, effects
nothing when it is at rest. Variation
answers to the wind ... Its course is
controlled by natural selection, the action
of which, at any given moment, is
seemingly small or insensible; but the
ultimate results are great.”
1876

47. Darwiniana
“Darwinian evolution (whatever may be
said of other kinds) is neither theistical
nor nontheistical. Its relations to the
question of design belong to the natural
theologian, or, in the larger sense, to the
philosopher. So long as the world lasts it
will probably be open to any one to
hold consistently, in the last resort,
either of the two hypotheses, that of a
divine mind, or that of no divine mind.”
1876

48. Theistic Evolution
“It seems to me absurd to
doubt that a man may be an
ardent Theist & an
evolutionist.— You are right
about [Charles] Kingsley. Asa
Gray, the eminent botanist, is
another case in point— What
my own views may be is a
question of no consequence
to any one except myself.”
- Darwin to John Fordyce, 1879