Comments about First Essay

I have distributed the graded first essays. Many of you would have benefited greatly from submitting something early and revising. Hopefully you will take into account my comments and seek help if you need it before tackling your final essay. If you weren't in class today, you can pick up your essay from me in my office during regular office hours or find me at another time.

Some of you seem rather at sea with regard to how to handle citations/references. For the final essay, please follow this formatting guide that describes a standard way of handling in-text citations. It's but one way, yes, but good practice to master it. I will include your successfully following it in the first row of the rubric on the final essay. Please ask if anything is unclear.

Here's how I see the scores on the rubric translating into rough grades: The A range runs from 22-28, B: 16-22, C: 10-16, D: 4-6, F: <4. But don't focus on the grade: focus on what you need to do to improve. Almost all of you needed to drastically increase the focus and specificity of your thesis. This, as I've been saying, sets the terms of a successful essay. It's much easier to argue well for a specific thesis. Please come visit with me sometime if you're not sure how to improve your work for the final essay. I'll be happy to read a draft or outline, talk about your thesis and argument, and help you structure your essay and tighten up your writing.

Assignment 10 (due 4/1)

Formalize Kitcher's argument against reductionism, describing the premises, general principles, and important background assumptions he draws upon as clearly as you can.

Meeting 11: The Reduction/Anti-Reduction Debate (4/1)

Reading:

• S&D Chapters 6–7: “Mendel and Molecules”, “Reduction: For and Against” **
• Sarkar, “Reduction: A Philosophical Analysis” [PDF]
• Kitcher, “1953 and All That: A Tale of Two-Sciences” [CIEB §13]
• Waters, “Why the Antireductionist Consensus Won’t Survive the Case of Mendelian Genetics” [CIEB §14]
• Sober, “The Multiple Realizability Argument Against Reductionism” [CIEB §15] *

Presentation:
Troy | Zoe commenting

Sterelny and Griffiths provide an excellent introduction to the main issues surrounding the reductionist anti-reductionist debate. We can get into this debate by noting the obvious fact that there are a number of different scientific theories (some coming under the heading of an umbrella theory, like biology, perhaps). How do all these different theories relate? Sometimes this relation seems quite unproblematic. Newtonian mechanics simply replaced Galilean mechanics; their relation is that one is closer to the truth than the other and that’s it. But there are also many theories which have a more questionable relationship. We'll focus on the test case of Mendelian genetics and it's relationship to modern molecular biology. Is the latter reducible to the former? What precisely does (or might) that mean? For that matter, is biology an autonomous science or can it all be reduced to physics? Is all science, as Ernest Rutherford put it, “either physics or stamp collecting”?

A terminological note for the Kitcher paper: it uses an older symbolic logic notation that you might not be familiar with. On p. 265, principle (*) reads: ‘(x)(x is a gene <—> Mx)’. This is to be read (in “quasi-English”) as ‘For all x, x is a gene if and only if Mx’. In other words: ‘All genes are Ms, and vice versa’, where ‘Mx’ is an “open sentence”, which basically means a complex predicate — something that can be said of something.

What is going on on page 266? All that’s happening is one direction of (*) — confusingly listed there as (2) — is being used to replace every mention of genes (Gx, Gy) with their molecular equivalents (Mx, My). Don’t worry about it if it’s still obscure. . . . The basic idea is just that (*) and (2) are being used as “bridge principles” for replacing the predicates of classical genetics with those of molecular.

Upcoming Meetings

I'm moving this post to the front: now with actual links (sorry about that delay) for you to use to start planning your presentation. Your final research essay will involve more sources than just these. I'm happy to help you with your search.

10. Organism and Environment — 3/25

• Lewontin, The Triple Helix (entire book)
  
• S&D Chapter 9: “Adaptation, Ecology, and the Environment” **

11. Reductionism versus Anti-Reductionism — 4/1

• Sarkar, “Reduction: A Philosophical Analysis” [PDF]
• Kitcher, “1953 and All That: A Tale of Two-Sciences” [CIEB §13]
• Waters, “Why the Antireductionist Consensus Won’t Survive the Case of Mendelian Genetics” [CIEB §14]
• Sober, “The Multiple Realizability Argument Against Reductionism” [CIEB §15] *
• S&D Chapters 6–7: “Mendel and Molecules”, “Reduction: For and Against” **

No class on 4/8 (Slater at Pacific APA).

12. Biological Laws & Contingency — 4/15

• Beatty, "The Evolutionary Contingency Thesis" [CIEB §11]
• Sober, “Two Outbreaks of Lawlessness in the Philosophy of Biology” [CIEB §12] *
• Lange, "Are There Natural Laws Concerning Particular Biological Species?" [PDF]

13. Biological Laws and Special Science Autonomy — 4/22

• Rosenberg, “How is Biological Explanation Possible?” [PDF]
• Lange, “The Autonomy of Functional Biology: a Reply to Rosenberg” [PDF]

14. Ecological Diversity, Biodiversity — 4/29

• Mikkelson, “Ecological Kinds and Ecological Laws” [PDF]
• Sarkar, “Defining ‘Biodiversity’; Assessing Biodiversity” [PDF]

Inland Northwest Philosophy Conference on "The Environment" — 5/1–3

15. Final Presentations: Topics TBA — 5/6

• If you are presenting in Meeting 15, final essays are due by Friday 5/15 at 3PM
• They are due Monday 5/11 by 3PM otherwise.

Assignment 9 (due 3/25)

What conception of the environment does Lewontin appear to be targeting in his discussion. Describe it in some detail and explain what he believes is wrong with this conception. What view of the environment does Lewontin advocate?

Meeting 10: Organism and Environment (3/25)

Reading:

• S&D Chapter 11: “Adaptation, Ecology, and the Environment” **
• Lewontin, The Triple Helix

Presentation:
Brian | Graham commenting

We switch gears next time to tackle the interconnections between gene, environment, and organism. Richard Lewontin has been an influential critic of genetic determinism and traditional views about the relationship between organisms and the environment. This book weaves together several of his criticisms into a fascinating, holistic (but not obscurely so) view of biology.

Rather than attempt to summarize the structure of the discussion, I shall leave you to enjoy Lewontin, who is a wonderfully clear writer. My goal for the our discussion, however, will be to try to clarify and evaluate the specifics of Lewontin's proposals, particularly about the relationship between organisms and their environments, but also between genes and organisms. As you'll see, much of the book will also be relevant to our discussion in meeting 11 about reductionism.

Study Questions

• Lewontin contends that discussion of development is fraught with bad metaphors. What specifically are his main concerns?
• What does the Clausen, Keck, and Heisey experiment show?
• Why would Lewontin dispute the claim that knowing an organism’s genome would allow us to specify all of its physical properties?
• According to Lewontin, how should we understand locutions like 'Gene X is for green eyes'?
• What is the difference between "forward" and "backward" modes of adaptive explanations?
• How does Lewontin understand the environment?
• What is the Red Queen hypothesis?
• Why does Lewontin think that "'The environment' does not exist to be saved" (68)?

the plan

Rather than mess up the whole schedule by going back to the HPC/SPC account of natural kinds, as my previous posts indicate, I think we ought to press ahead. We'll spend a little time talking about SPC kinds next time, since I think they're relevant to questions about the reality of race.

Here's what I want to do for your assignments. If you did them: great. Why don't you email me a copy. If you did not: no worries, I'll give you a free pass.

If I'm not mistaken, David was planning on presenting in our next meeting (correct, David?). Would someone like to volunteer to comment on his paper? If all goes as expected, it should be ready by the weekend. Feel free to use the comments: one bonus of using blogger, I guess.

Race Resources

There is a quite a wealth of information on the science of race online. Here's an excellent place to start: http://www.racesci.org/. Richard Lewontin also lectured on the topic a bit ago (video).

See also the reading list for Sally Haslanger and Koffi Maglo's course at MIT on Race.

Assignment 8 (due 3/11)

Respond to two to three study questions for Meeting 9.

Meeting 9: Are Races Real (3/11)

Readings:

• Appiah, "Why There Are No Human Races" [CIEB §22]
• Andreasen, "A New Perspective on the Race Debate" [CIEB §23]

We turn this week to the question of the reality of race. Do our racial concepts correspond to anything genuine in reality or are they merely social constructs? From this simple starting point, lots of interesting methodological issues arise: does the question of the reality of race automatically engage our concepts? Andreasen suggests that it might not. Perhaps there are (real) races and our ordinary understanding of what they are is flawed. In Sober’s introduction to the section on race, he offers an apt analogy to the one time presumption that whales are fish. We can revise this view on the influence of new information without rejecting that fish are a taxonomically-respectable group. Andreasen’s essay attempts to make biological sense of races as subspecies on a cladist model of taxonomy.

Appiah’s approach is different: he is a skeptic of race, placing a great deal of emphasis on the question of whether there is anything in biology that might vindicate our ordinary concept. His approach bears some resemblance to skepticism about the reality of species from the apparent lack of essential properties characterizing them.

As you might expect, my take on this issue is somewhat different: I’m not convinced that what we ought to be looking for is biological reality. Here the HPC/SPC kind view might help some, as it is not a specifically-biological account. I’m not yet sure how the details might go — what the clustered properties would be, whether presumptive clusters would feature the sort of stability (or homeostasis) required, and so on. My suspicion is that there might be something in the neighborhood of stable clusters of biologically/culturally-interesting properties/dispositions that might feature a kind of dwindling stability (think back to the discussion of metastability).

Study Questions

• Describe the difference between the “ideational” and the “referential” views of meaning.
• How does the analogy to acids work for Appiah?
• In what sense does Appiah see Jefferson as interested in a BIOLOGICAL conception of race?
• Compare Appiah’s take on Jefferson and Arnold on the race question.
• Describe the relevance of evolution to the race question. Do Appiah and Andreasen see its relevance in the same way?
• What, in brief, is Appiah’s argument that there are no human races?
• Describe the “no subspecies” argument against the reality of race (both varieties). How does it differ from the “no human subspecies” argument?
• How does Andreasen propose to use cladism to understand human races?

Lewontin at Book People

I'm told that Book People has a bunch of copies of Lewontin's The Triple Helix. Please pick yours up soon --- I don't know that they're saving them for us or something.

New Course Blog for PHIL 417/517

Oy veh: the program I've been using to take care of my personal blog and Phil Bio course blog has managed to corrupt all of those posts. So I've reconstructed the blog on Blogger, which I take it will be a bit more reliable [knocking on wood].

More Suggested Essay Topics

Here are some further topic ideas you might think about for your first essays. Note that you should not simply think of yourself as answering these questions: you should develop a specific thesis and argue for it carefully, in depth. I am also happy to direct you to further readings on your chosen topic (the Sober collection is generally a good place to start, as is the Sterelny and Griffiths book).

• Examine the merits of evolutionary psychology. Clearly, some of its proponents go too far; does it ever provide us with genuine illumination about certain features of our society or psychology?
• Are Buller and Haufe's criticisms completely fair or is there some way for evolutionary psychologists to respond?
• Does Neander succeed at making room for teleology (proper functions) in a mechanistic world? Evaluate her case.
• Paul Davies argues that the systemic capacity theory of functions actually subsumes selected effects functions — does he succeed?
• Are “malfunctions” impossible? Davies claims so in his paper “Malfunctions” [PDF] (the argument is also sketched in his “The Nature of Natural Norms”). Evaluate this claim.
• Dupré and Kitcher suggest that we ought to be pluralists about natural kinds. Evaluate their arguments.
• What are the prospects for natural kinds essentialism? Does Devitt make a compelling case for recognize at least partly intrinsic essences?

Assingment 7 (due 3/4)

One initially plausible objection to my SPC account of natural kinds concerns the specific notion of stability: doesn't this account imply that there can be no natural kinds of unstable elements? For instance, am I committed to the thesis that Uranium-238 is not a natural kind? Surely this would be a good reason for rejecting my account. Do me a favor and construct a response on my behalf.

If you cannot see that this objection has a good response, try to develop it in the most forceful way you can and explain why you do not believe that a response is possible.

Meeting 8: A Different Kind of Natural Kind (3/4)

Readings:

• Boyd, “Homeostasis, Species, and Higher Taxa” [PDF]
• Slater, “Why the Long Face? The Stable Property Cluster Account of Natural Kinds” [PDF]

As we've seen, the thesis the biological taxa have essential properties (like those supposedly possessed by physical and chemical kinds), looks rather implausible. Since the concept of a natural kind is usually bound up with notion of an essence — a defining characteristic of the kind —, the fall of essentialism has meant for many a denial that species (and other biological taxa) are natural kinds. Indeed, this is a major motivation behind the move to the species-as-individuals thesis. If species are real and not natural kinds, then they must be individuals! I believe that this argument possesses a false premise (that species are not natural kinds) and is fallacious (in particular, it seems a false dilemma to think that species must be either natural kinds or individuals. Perhaps species might fit in another ontological category or perhaps, as I suggested in my "Contentious Metaphysics of Species" paper, species might not be anything and we should instead focus on how to reconstruct talk of species in an ontological non-committal way (e.g. using plural quantification).

The thesis that natural kinds must possess essences, though natural and popular, does not seem to be part of the concept of a natural kind. Their inferential and explanatory role is, to my mind, more central. We’ll focus on a strand of anti-essentialism committed to this stance. Richard Boyd (a philosopher at Cornell) is perhaps the best known defender of anti-essentialism about natural kinds — though I should immediately point out that it is somewhat controversial whether his view should be reckoned as "anti-essentialist" (this is something I'll want to talk about). He defends what he calls a “homeostatic property cluster” (HPC) account of natural kinds on which rather than an essence maintaining the correlation among a bunch of properties we associate with a given kind, the properties, in a way, correlate themselves. No one property among this “cluster” of properties need be regarded as the essence of that kind — they all are. Nor must we view all of the properties as necessarily possessed by members of the HPC kind. The relevant homeostasis may be imperfect, after all.

I find this picture very appealing. But I’m not certain what counts as a homeostatic mechanism and what is meant by certain phrases Boyd uses to cash out this notion: “the causal structure of the world” and so on. This quibble can be answered, I suppose. One answer I can imagine is: “Oh, come on! You know well enough what I mean by ‘the causal structure of the world’! It’s the whole causal economy: the way things work, how everything fits together, what science studies.” But even supposing something like this helped (and I don’t see that it does), a bigger problem for the HPC view is that the kind of homeostasis that Boyd assumes is present is often apparently lacking: say, for higher taxa, species undergoing disruptive selection, or taxa (at the species rank and otherwise) whose coherence is maintained by “phylogenetic inertia”. It seems to me that all we are really committed to with the reality of species is their broad explanatory utility and this can be secured simply by the stability that the relevant cluster of properties features. I defend this thesis in more detail in my “Why the Long Face?” using examples other than species. The paper is a bit on the long side (sorry — this is actually the SHORT version, believe it or not), so you can skim section 2 if pressed for time (you've already heard my views on many of these issues).

Study Questions

• Briefly describe what an HPC natural kind is. How does it help address the problems facing typological thinking?
• What is Boyd’s accommodation thesis?
• How does the essentialism espoused by Boyd differ from a more “traditional” essentialism about natural kinds?
• What is Boyd’s stance on species pluralism?
• How do explanatory and programmatic definitions differ?
• Does Boyd think that there is an important distinction between species and higher taxa (such as genera)?
• Peacocke draws a distinction between narrow- and wide-scope explanations. Describe it and explain how it is relevant to the discussion of the HPC account.
• Describe a criticism of mine of the HPC view. Do you think Boyd could offer a compelling response?
• What specific problem is posed by disruptive selection?
• What is metastability and how might it be relevant to the discussion of HPC kinds?
• Why is stability important for a potential understanding of natural kinds? What role might it play in such understandings?
• How does the SPC account differ from the HPC account?

First Half Essay

Remember: I will be recording your first essay score for your best essay I receive by March 11th (in about two and a half weeks!). Remember: you can write as many as you like (and up to two versions of the same essay) and I will only count your best. I strongly recommend you take advantage of this golden opportunity, as I'll be holding you to the high standard expected of a 400/500-level course (according to your specific affiliation).

Specifically, I will be using this rubric to mark your essays. Worry about the tiles of the columns, not the numbers (which will not correspond in the usual way to grades): to get an 'A', you should expect to have most marks in the 'excellent' / 'very good' columns. A 'B' paper will be more centered around the 'very good' column; with 'C', 'D', 'F', as you'd expect. . . . I'll curve numerical scores to reflect this. Bear in mind, however, that as time approaches (if I'm getting lots of submissions at the same time, my ability to turn around the paper quickly for you to revise or rewrite completely will decrease; the sooner you get me something, the more likely it is that you'll be able to revise it into something better)

I highly recommend going through multiple drafts before submitting something. Take account of the writing advice on my website along with the associated links. I can't recommend the "Bennett Rules" — see Bennett and Gorovitz’s essay on “Teaching Academic Writing” — highly enough. Ask yourself honestly whether the paper is as clear and precise as it can be. Write not only so that you can be understood, but so you cannot be misunderstood.

Assignment 6 (due 2/25)

Pick two of the study questions for Meeting 7 to answer in no more than one sheet total (it may be double-sided).

Meeting 7: Resurrecting Essentialism? (2/25)

Readings:

• Okasha, “Darwinian Metaphysics” [PDF] *
• Devitt, “Resurrecting Biological Essentialism” [PDF]
• Slater, “Biological Laws and Essences” [PDF]

So far we've seen several philosopher pile on against the thesis that species (or other biological taxa) should be treated as natural kinds in the Kripke/Putnam essentialist mold. A central part of the motivation for the species-as-individuals thesis the denial of biological essentialism; ditto for Mayr's resistance to typological thinking in favor of population thinking. There's something of a consensus forming that species lacked essential properties --- intrinsic properties which made them the sorts of things they are.

Michael Devitt has very recently critiqued this consensus as unargued for dogma and presents a new argument in favor of the thesis that biological taxa do in fact possess "at least partly intrinsic" essences. Along the way, he makes a number of important and interesting points worth discussing. Continuing in my critical vein --- you'll have something positive from me at last next week! ---, I argue that Devitt's case for essentialism falls flat. This is not, notice, to argue that essentialism is false --- that's something I want to talk about in more detail with you --- just that we do not yet have good enough reason for being very confident about essentialism.

To foreshadow a later topic a bit, you might give some thought to the role that biological laws play in Devitt's argument. Many philosophers, as you'll see, are deeply skeptical of the idea that there are any distinctively biological laws (let alone laws about particular species). On the other hand, some (like Sandra Mitchell and maybe Marc Lange) hold a view that seems to regard laws as coming in degrees. I'm going to try to write a further section of my paper on how that sort of view might affect the essentialist thesis.

Study Questions

• What, specifically, do you take Devitt's thesis to be? Try to explain it in detailed, neutral terms.
• Devitt mentions an important distinction between a "taxon problem" and a "category problem": what is this distinction?
• How might the taxon and category problems relate to each other?
• How is the above distinction important to Devitt's argument?
• How does Devitt propose to avoid the anti-essentialism purportedly implied by relational species concepts?
• What are Devitt's two arguments for Essentialism?
• Does Slater miss anything in interpreting these arguments? (No really: do I?)
• Describe (and critically evaluate) Slater's criticism of Devitt's first argument.
• Describe (and critically evaluate) Slater's criticism of Devitt's first argument.
• What is the "Monsters Problem" and how does Devitt respond to it?

Meeting 6: The Species Problem & the Metaphysics of Species (2/18)

Readings:

• S&D Chapter 9: “Species” **
• Hull, “A Matter of Individuality” [CIEB §18] **
• Kitcher, “Species” [PDF]
• Crane, “On the Metaphysics of Species” [PDF] *
• Slater, “On the Contentious Metaphysics of Species” [PDF]
• Slater, “Against the Individuality of Species” [PDF] **

There is a sense in which evolution both simplifies and complicates biological taxonomy. For some, it simplifies it by making sense of the interrelatedness of different species, the hierarchical, nested structure of biological similarity, and so forth. On this conception, species should be thought of as "hunks of the genealogical nexus" or "segments of the tree of life". Of course, this broadly historical perspective does not tell us much about how to segment the tree of life. On the other hand, it sometimes seems as though similarity (in some sense) is of primary importance for classification. Common historical origin might help explain this, but we needn't regard history as of primary importance for taxonomy. So what are species?

In an oft-quoted letter to Joseph Hooker (24 December 1856), Darwin took the difficulty of reaching agreement about a correct conception of species as well-nigh insuperable:

It is really laughable to see what different ideas are prominent in various naturalists’ minds when they speak of species; in some, resemblance is everything and descent of little weight — in some, resemblance seems to go for nothing, and Creation the reigning idea — In some, descent is the key, — in some, sterility an unfailing test, with others it is not worth a farthing. It all comes, I believe, from trying to define the indefinable.

I think he was too quick to give up, but it’s notable that the same sort of disagreements persist: on one recent count, there were over twenty different species concepts being actively pursued. Is just one of these the correct one? Or perhaps we haven't yet come up with the correct species concept. . . . The issue of whether there is just one privileged conception of species (or biological taxa generally) is often referred to as the debate between "monism" and "pluralism" about species. Kitcher contends that we should be pluralists about species — there is no uniquely correct way of dividing up biological reality. Yet, this doesn't mean that species are not real or that there are objective divisions between different biological groups. So he claims. We'll want to talk about this.

The question What are species? has a different sense. Rather than asking after the conditions under which some organisms belong to a species taxon, we might be interested to know into what ontological category these taxa belong. What is an "ontological category"? This in itself is a somewhat fraught question, but the basic idea is that it is a fundamental category of being: for example, objects, processes, events, properties, sets, numbers, propositions, and so forth might all be considered as such categories. If I ask you What are tables? You might respond by trying to tell me the specific conditions under which some pieces of wood compose a table. Or you might start much more generally by telling me that tables are a certain sort of object, thus distinguishing them from properties or events. Tables and wars are in different ontological categories: the former are objects, the latter are events.

Now then: What sort of thing are species? To what ontological category do they belong? We've already seen some concern about treating species as natural kinds (to some, as certain kinds of sets or classes). Perhaps we should consider an alternative. In this spirit, Michael Ghiselin proposed a "radical solution to the species problem":

It would appear that the philosophy of taxonomy is about to undergo a major upheaval. Symptomatic is its Gordian knot, the species problem. Some years ago (Ghiselin, 1966a) I attempted to cut it with the sword, casually remarking that, in the logical sense, species are individuals, not classes. (1976, 536)

The idea seems to be that if we treat species as classes (that is, sets or collections of organisms), we force ourselves into Mayr’s dreaded typological thinking. For the reality of the class would only be secured by some defining essence shared by all (and only) its members. But typology in this sense appears implausible. Perhaps some things have essences (gold, water, electrons, &c.), but the essentialism appears ill-suited to the “blooming, buzzing confusion” of the biological world.

The case was taken up by David Hull, an influential philosopher of biology (now emeritus at Northwestern), who offered many reason for treating species as individuals (though it is not always clear what precisely he means by this term). You might think as you’re reading whether his reasons for defending the thesis shed more light on the details of his thesis. What are his reasons? Are the good?

This is where Kitcher’s paper on “Species” picks up: he suggests that Hull fails to offer us good reason for accepting the species-as-individuals (SAI) thesis. Kitcher defends the view that species are certain kinds of sets, arguing that this thesis becomes a straw-man in Hull’s essay. But Kitcher takes the species problem seriously. Perhaps we go wrong to assume that there is just one privileged species concept. But does a plurality of species concepts imply that species are not real? He thinks not. We can be pluralistic realists about species. I suspect that we may want to put this case off for another week or so.

Despite Kitcher's criticisms of Ghiselin and Hull, SAI is more popular than ever. My paper "On the Contentious Metaphysics of Species" critiques some recent arguments for SAI in the context of the early arguments. Of course, even if our criticisms hit their mark, SAI might still be true (don't confuse the truth of a thesis with its pedigree). This is roughly the sense I’ve gotten from many philosophers of biology over the years: "yes, Hull makes an inconclusive case for SAI — but it’s still the best metaphysics of species." Even Kitcher later contended that the issue doesn't bear on anything: one can equally well construe species as individuals or sets. I disagree. My paper "Against the Individuality of Species" makes the case that SAI incurs certain expenses that biologists should not front! As this case is primarily metaphysical (trading in particular on particular theses about ontological vagueness), those non-philosophers of you might find things a bit opaque (hence its being optional). But if you’re interested in getting some further background on vagueness, I can recommend Roy Sorensen’s SEP entry and Achille Varzi’s (2001) article “Vagueness, Logic, and Ontology” (particularly the section on ontological versus semantic vagueness).

Study Questions

• Explain how the SAI thesis might fit into the debate about typology versus population thinking.
• How does Kitcher’s assertion that “there is no inconsistency in claiming that species are sets and denying that the members of these sets share a common property” (310) answer one of Hull’s arguments for SAI?
• Describe and evaluate Kitcher's arguments for pluralism.
• Explain some objections to the biological species concept.
• Do you think that pluralism is compatible with realism about species?
• Describe Kitcher's lizard example and what it is intended to show.
• What is the difference between historical and structural explanations? How does this distinction bear on the case for pluralism?
• Does pluralism involve the claim that any species concept is acceptable? Why or why not?
• Why is problematic for SAI-ists to adduce the necessary spatiotemporal connectedness of species as evidence for SAI?
• What is Crane's argument for SAI and what difficulties does it face?

Assignment 5 (due 2/18)

Summarize Kitcher's basic argument for species pluralism as carefully and precisely as you can. If space allows, comment on any potential weak points or premises that appear to need further discussion or support.