Course Outline for Philosophy 2233- The Earth and Life Sciences: Spring 2010
Instructor:
Bryson Brown, UH 864.
Phone: x2506 Email: brown@uleth.ca
Office Hours: 10-11 M/W and by appointment.
One aim of this course is to study the relation between rational belief and scientific evidence. In
the seventeenth century it was fairly reasonable for a well-informed European to hold that the Earth was on
the order of six thousand years old, and that the various plants and animals we see were separately designed
and created. But today this view is regarded as naïve; scientists (and well-informed people in general)
believe that the Earth is about 4.6 billion years old, and that life on Earth is descended from a common
ancestor dating back 3.5 billion years or more.
We will try to understand this change by examining the history of the earth and life sciences,
focusing on the arguments and evidence that led us from a worldview based on Genesis to the worldview
scientifically accepted today. In the first section of the course we will examine the development of modern
geology; then we turn to the history of biology and the process of evolution. The last section of the course
will focus on the relation between evolution and ethics.
Along the way we will consider some philosophical issues, including the nature and status of
evidence about the past, different accounts of scientific method including inductivism, falsificationism and
inference to best explanation, and links between scientific theories, naturalism, and wider questions
including ethics, religion and the meaning of life.
By common sense standards, evidence about past events can be extremely convincing. But we
rarely ask ourselves what makes it so convincing. Normally this doesn’t cause much trouble; for the most
part common sense works pretty well all by itself, without reflection on the hows and whys. But when we
don’t understand how we come to have the evidence we do and why it justifies our beliefs, we leave
ourselves vulnerable to clever skeptical arguments. Consider this: Any evidence we have now about the
past must be facts about the present— facts about things like memory traces, inscriptions and recordings,
fossils, fault lines, strata and their geological arrangements, the light from distant stars and so on. So how
do we justify the claim that this presently available evidence reliably indicates how things were in the past?
Don’t we need some further, more direct evidence about how things worked in the past, to justify the claim
that these present traces really provide reliable information about the past? And if we do need such
additional evidence, aren’t we stuck with an unsolvable problem, since all the basic evidence we have now
depends only on how things are now? We’ll examine this issue & consider carefully what sort of evidence
we need to justify historical claims. One lesson here is that the popular creationist tactic of rejecting
evidence about the distant past because there were “no witnesses” depends on a serious misunderstanding
of how evidence about the past really works.
Scientific inquiry has led us to a rich history of the earth and of life on earth. Understanding how
we arrived at this history requires careful thinking about how science works. There have been many
different philosophical answers to this question; we’ll examine some of these. Once again we will find that
creationist arguments depend on naïve misunderstandings of how science works. One especially common
pattern is insisting on standards of proof in science (or at least in those parts of science that creationists
object to) that no human knowledge could pass.
Induction is one important concept in the neighbourhood. Whenever we reason from what we
have observed to conclusions about the unobserved, we are using inductive reasoning. Traditional
examples of induction focus on generalizations that we make about objects of various kinds & how they
behave under various circumstances. Some of these are just plain part of common sense: we expect
unsupported objects to fall; we expect hot things to burn us if we touch them; we expect the foods that
nourished us yesterday or last week to do the same again today and tomorrow. Induction has often been
described as a process of “projecting” such observed regularities onto unobserved cases. But there are
problems for this picture, as a famous paradoxical argument from Nelson Goodman shows. Further, even if
something like this picture is correct, there are difficulties in understanding what reasons we could have for
accepting it. It does seem that it has worked in the past. But this is really just another observed regularity,
and we need a reason to suppose that this regularity will continue in the future, before it would be rational
to accept that it will. This is the gist of Hume’s famous argument that the past success of induction cannot
provide non-circular reason to accept induction. Hume also argued that there was no good deductive reason
to suppose induction is reliable, and concluded that inductive reasoning is not rationally defensible.
However, Hume also believed that we will do it anyway, because we are (in effect) programmed to reason
inductively whether we want to or not—a claim that itself seems to depend on induction for support!
An influential twentieth century philosopher of science named Karl Popper agreed that induction
was indefensible, and concluded that science, properly understood, shouldn’t use induction at all. Instead,
he thought that it should use the method of falsification, or (as he later put it) of ‘bold conjectures and
refutations.’ According to Popper’s account of scientific method, scientists make guesses about
generalizations that might hold, and then test them as severely as they can, trying to find ways to make
them fail. The body of scientifically acceptable theories, from this point of view, is really just a list of
generalizations that haven’t been falsified yet.
But without some role for induction we are left with no justification for any claims we make as to
how things will turn out in the future, even though all of our practical efforts seem to be based on such
commitments: When we design a bridge, plant a crop, or use a tool we assume that certain regularities will
continue. In fact, we often bet our lives on it! So some account of induction is essential if we are to have
any account of why some practical choices are rational and some are not.
More recently, some epistemologists have proposed inference to the best explanation as an
account of how we extend our observations to a justified story about the wider world. While some
philosophers of science have endorsed this shift of focus, from confirmation to explanation, others have
resisted, seeking a more traditional account of the relation between theories and the observations that test
them. But the role of explanation in our understanding of the world goes right back to the roots of common
sense; any account of scientific method will need to recognize the importance of explanation to the
justification of beliefs. A successful account must also account for some important limits on the reach of
explanatory hypotheses (as the “god of the gaps” example shows). We’ll examine these debates & try to
arrive at a broader understanding of scientific method, with an eye on important examples from geology
and biology.
Finally, many creationists have argued that ethics and evolution are somehow incompatible. One
of the key issues we need to explore here is how normative and descriptive concepts are related to each
other. Some have argued that they are completely distinct and independent, so it may turn out that there
can be no conflict between science and ethics: Ethics is essentially normative, while science aims to
provide correct descriptions of the world. But the descriptive and the normative may not be completely
independent, and evolution may have real implications for our understanding of ethics (the creationists’
incompatibility claim is still very hard to defend, even if we allow for some plausible connections). Here
S.J. Gould’s defense of the doctrine of “separate magisteria” will be examined, as well as Hume’s concerns
about the relation between normative and descriptive claims.
We have two main texts, as well as some further short readings. The texts are both available in the
bookstore: The Abyss of Time, by Claude Albritton, and The Discovery of Evolution, by David Young.
Some additional short readings are taken up at the end of the course to cover issues connecting ethics,
social thought and evolution.
Other recommended readings:
D.J. Futuyma, Science on Trial (Sinauer, 2nd ed. 1995).
D. J. Futuyma, Evolutionary Biology 3rd ed. (Sinauer 1998).
G. Gohau, A History of Geology (Rutgers University Press, 1990)
Stephen Jay Gould, Ever Since Darwin, The Flamingo=s Smile, Bully for Brontosaurus, Time’s Arrow,
Time’s Circle, Rock of Ages, Eight Little Piggies, The Lying Stones of Marakesh, Leonardo’s Mountain of
Clams,,,
A. Hallam, Great Geological Controversies, (Oxford, OUP, 1983).
Rachel Laudan, From mineralogy to geology : the foundations of a science, 1650-1830, University of Chicago
Press, 1987.
John McPhee, Basin and Range, Rising from the Plains, In Suspect Terrain, Coming into the Country, and,
finally, Annals of the Former World Farrar, Strauss and Geroux, NY, 1998 (collects the others & more).
R. Pennock, Tower of Babel: The Evidence Against the New Creationism, MIT Press, 2000.
Martin Rudwick, Bursting the Limits of Time (Chicago, 2007), The Meaning of Fossils (Chicago 1985, first
ed. 1972)
Michael Ruse, Darwinism Defended (Benjamin/Cummings)
Steven M. Stanley, Earth and Life Through Time 2nd ed. W.H. Freeman & Co., 1989.
Phil 2233- Course Schedule and Grading Scheme
Course Schedule:
Week 1: Jan 6, 8: Introduction, overview of material: Change in view, evidence and reasoning, certainty and
skepticism. Nicholas Steno, Solids within solids and the principles of stratigraphy
Week 2: Jan 11, 13, 15: Two views on the nature of fossils; Kircher, Hooke. Reasoning about the past—memory and
other traces; the reliability of evidence about the past & our accounts of various processes.
Week 3: Jan 18, 20, 22: Two images of time: Time’s Arrow—Burnet, De Maillet, Buffon; Time’s circle—Hutton and
Playfair.
Week 4: Jan 25, 27, 29: William Smith and fossil stratigraphy: a new arrow of time. Evidence for Smith’s hypothesis
& its independence from evolutionary assumptions. Werner’s geognosy & the neptunist’s arrow.
Week 5: Feb 1, 3, 5: Uniformity principles: catastrophism vs. actualism vs. uniformitarianism, Cuvier, Scrope, and
Lyell. Methodological advantages of uniformitarianism. The ice age (Perraudin, Venetz, Charpentier & Agassiz) &
how theories become facts. The role of naturalism in scientific thought.
Sample questions for test 1 distributed October 5.
Week 6: Feb 8, 10, 12: The Age of the Earth – Kelvin and the geologists. Conflict in science, and how to cope with it.
Radiometric dating. Plate tectonics.
Test 1- February 12. READING WEEK: February 15-19. No classes.
Week 7: Feb 22, 24, 26: Introduction to evolution. Ancient ideas about life, the shellfish on the mountaintop, natural
teleology.
Week 8: Mar 1, 3, 5: Life’s history and geography.
Week 9: Mar 8, 10, 12: The question of species; the puzzle of adaptation and the argument from design.
Week 10: Mar 15, 17, 19: Darwin, natural selection and adaptation.
Sample questions for test 2 distributed Mar 17.
Week 11: Mar 22, 24, 26: Genetics and selection: The development of the modern synthesis.
Test 2- March 26
Week 12: Mar 29, 31: Social Darwinism and its failings. Hume and the is/ought gap.
Week 13: April 7, 9: Evolution and altruism: kin selection, group selection, selfishness and selflessness, genes and
individuals.
Week 14: April 12, 14, 16: Ethics, values, and their relations to evolution and the natural world in general.
Sample questions for final distributed April 14.
Grades: Grades will be based on two term tests (35 % each) and a final exam (30%). The tests combine short answer
questions (answers to these should range between a single sentence and a paragraph in length) and essay questions
(answers to these should range from a couple of pages up). Short answer questions focus on the material covered in the
texts and lectures, while the essay questions provide an opportunity to show both a grasp of the material and the ability
to think seriously about it. Your personal views will not be part of the basis for your mark; your grasp of the material
and the arguments you offer will be. The final exam will have a similar structure, with short answer questions drawn
from the topics of the last few weeks (evolution and ethics, broadly) and essay questions ranging over the whole
course.
Policy On Academic Offenses:
Plagiarism and other forms of academic cheating are serious offenses (for definitions & further info, see
Student Discipline Policy in the University of Lethbridge Calendar). In the case of a first offense, a 0
mark will be entered for the test or assignment in question. In the case of a second offense, an F will be
entered as the course grade. In either case a notice will be added to the student’s file, and further action
may also result.