Associate Professor, Department of Philosophy, Lewis & Clark College

Evolution and Ethics

Added on by jay odenbaugh.

Let's define moral realism as the view that there are objective moral truths. There are many different arguments for and against the view of course. However, recently there has been a lot of work on evolutionary "debunking" arguments against moral realism. We can sketch the argument as this: 

  1. ur moral beliefs are explained by evolution by natural selection. 

  2. However, evolution by natural selection is an "off-track" process; it is not concerned with truth but reproductive success. 

  3. Off-track processes do not produce justified beliefs. 

  4. Therefore, our moral beliefs are unjustified. 

Consider an analogy. Suppose that there is a species of plant A which is poisonous and another mimic species B which is not. Likewise, suppose A is found 90% of the time in our environment whereas B is found 10% of the time. If you encounter a plant and you don't know whether it is A or B what should you believe to maximize your reproductive success? Clearly, you should believe the plant is A. In this instance, your fitness is greater if you form false beliefs rather than true beliefs.  

Is this argument sound? Why or why not? 

Beatty on Biological Laws

Added on by jay odenbaugh.

Stephen Jay Gould famously consider the following analogy. Evolution is like a videotape which if replayed over and over would have a different ending every time. In effect, the evolution of living things is sensitive to initial conditions. If a system starts in slightly different initial conditions, the future states will depart even further. 

John Beatty develops this thesis into an argument against there being biological laws. He writes,

The thesis that I will defend, most briefly put, is this: all distinc- tively biological generalizations describe evolutionarily contingent states of nature – moreover, ”highly” contingent states of nature in a sense that I will explain. This means that there are no laws of biology. For, whatever ”laws” are, they are supposed to be more than just contingently true.

This is the evolutionary contingency thesis. Why does Beatty deny there are biological laws? Does this mean there are no laws that govern biological systems? 

Putnam's Peg Argument and Sober's Response

Added on by jay odenbaugh.

Hilary Putnam argues against reductionism on the basis of the "peg argument." Elliott Sober summarizes it as follows, 

Suppose a wooden board has two holes in it. One is circular and has a 1-inch diameter; the other is square and is 1 inch on a side. A cubical peg that is 15/16ths of an inch on each side will fit through the square hole, but not the circular one. What is the explanation? Putnam (1975) says that the explanation is provided by the macro-properties just cited of the peg and the holes. He denies that the micro-properties of molecules or atoms or particles in the peg and the piece of wood explain this fact. The micro- description is long and complicated and it brings in a welter of irrelevant detail. To explain why the peg goes through one hole but not the other, it does not matter what micro-properties the molecules have, as long as the peg and board have the macro-properties I mentioned. The macro-properties are explanatory; the micro-properties that realize those macro- properties are not. Hence, reductionism is false. (304) 

Sober's response goes as follows, 

Perhaps the micro-details do not interest Putnam, but they may interest others, and for perfectly legitimate reasons. Explanations come with different levels of detail. When someone tells you more than you want to hear, this does not mean that what is said fails to be an explanation. There is a difference between explaining too much and not explaining at all. (304-5)

Is this a reasonable response to the "peg argument"? Why or why not? 

Natural Kinds

Added on by jay odenbaugh.

According to some philosophers, the only way to explain why green is projectible and grue is not is because the former is a natural kind and the second is not. A natural kind is a group of entities such that they share at least one essential property. A common argument for the existence of natural kinds like GOLD, OXYGEN, or BOSON is that they best explain our experimental and predictive success. E.g. if you know that certain properties cluster together then you can predict what properties objects have. What do you think about this defense of natural kinds? 

Scientific Method and Social Values

Added on by jay odenbaugh.

Kathleen Okuhrlick claims that even if we accept the traditional distinction between the context of discovery vs. the context of justification, non-cognitive values (e.g. values unrelated to truth) can affect scientific theory choice. She writes,

My point, however, is that even if we grant for the sake of argument that scientific method is itself free of contamination by non-cognitive factors and the decision procedure operates perfectly at the nodes, nothing in this procedure will insulate the content of science from sociological influences once we grant that these influences do affect theory generation. If our choice among rivals is irreducibly comparative, as it is on this model, then scientific methodology cannot guarantee (even on the most optimistic scenario) that the preferred theory is true only that it is epistemically superior to the other actually available contenders. (201)

Question: How can non-cognitive values affect theory choice according to Okuhrlick? According to Okuhrlick, can we avoid having those values affecting scientific theory choice? 

Kuhn on Incommensurability

Added on by jay odenbaugh.
Traditionally, we think of successive scientific theories in a given domain as accumulating more and more truths about nature; we continually build on what we already know. For example, many have argued that Newton’s classical mechanics is just a special case of Einstein’s theory of special relativity. In classic mechanics, momentum is given by p = mv whereas it is given by p = mv [(1 − (v/c)^2] in special relativity. When v << c, then p mv. Newton’s theory is a special case of Einstein’s. Thomas Kuhn denies that Einstein’s theory merely accumulates the truths of Newton’s and provides additional ones because the two theories are incommensurable. Here is Kuhn in his own words.
Can Newtonian dynamics really be derived from relativistic dynamics? What would such a derivation look like? Imagine a set of statements, E_1, E_2,…, E_n, which together embody the laws of relativity theory. These statements contain variables and parameters representing spatial position, time, rest mass, etc. From them, together with the apparatus of logic and mathematics, is deducible a whole set of further statements including some that can be checked by observation. To prove the adequacy of Newtonian dynamics as a special case, we must add to the E_i’s additional statements, like (v/c)^2 << 1, restricting the range of the parameters and variables. This enlarged set of statements is then manipulated to yield a new set, N_1, N_2,…, N_m, which is identical in form with Newton’s laws of motion, the law of gravity, and so on. Apparently Newtonian dynamics has been derived from Einsteinian, subject to a few limiting conditions. Yet the derivation is spurious, at least to this point. Though the N_i’s are a special case of the laws of relativistic mechanics, they are not Newton’s Laws. Or at least they are not unless those laws are reinterpreted in a way that would have been impossible until after Einstein’s work. The variables and parameters that in the Einsteinian Ei’s represented spatial position, time, mass, etc., still occur in the N_i’s; and they there still represent Einsteinian space, time, and mass. But  the physical referents of these Einsteinian concepts are by no means identical with those of the Newtonian concepts that bear the same name. (Newtonian mass is conserved; Einsteinian is convertible with energy. Only at low relative velocities may the two be measured in the same way, and even then they must not be conceived to be the same.) (1962/1970a, 102)

Questions: For Kuhn, why are these two theories incommensurable? 


The Tautology Problem and Fitness as a Propensity

Added on by jay odenbaugh.
Suppose we define ’fitness’ as,
Fitness of an individual or type of individual as the actual number of offspring produced.
Likewise, suppose the average number of offspring of type x is greater than the average number of offspring of type y.

Why did x on average leave more offspring than y? Because x is fitter than y.

But, given the above definition,

Why did x on average leave more offspring than y? Because x on average left more offspring than y.

This is no explanation -- it seems to be a "tautology." Mills and Beatty write,

"The whole idea of setting up empirical investigations to deter- mine whether fitness differences are correlated with actual descendent contribution differences seems absurd, given the above definitions of fitness."
How does the Propensity Interpretation of Fitness resolve this problem? 


Adaptationism and Falsifiability

Added on by jay odenbaugh.

According to Karl Popper, a theory is scientific if, and only if, it could be shown false by observations. Richard Lewontin and Stephen Jay Gould criticize adaptationism in evolutionary biology when they write, 

"We would not object so strenuously to the adaptationist program if its invocation, in any particular case, could lead in principle to its rejection for want of evidence." (Sober 2006, 86)

Given their critique of adaptationism,  is evolutionary theory scientific in Popper's sense?