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//************ Laws in a Post-Kuhn World - October 10th, 2019 ***************//
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- Alright - we missed class on Tuesday due to some unknown pathogen assaulting our professor, so we've got some catching up to do!
- We'll cover our reading from Tuesday, and then hopefully get to Giere's paper for today
- We'll then talk about what's expected from you for your midterm
- So, let's talk about your midterm!
- The exam should be available later tonight; there are 4 questions on it, with instructions on Canvas on what to do
- PLEASE follow the instructions, like not putting your name on pages beside the title page so they can be graded blindly, and following the length restrictions
- I'd recommend getting close to the maximum length if you're worried about not going in-depth enough, but don't go over! Still try to be concise!
- The exam is open-note and open-book; as long as you're not plagiarizing or stealing ideas from another student, you're good!
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- As a backdrop to these papers, let's talk about REDUCTIONISM
- This is basically the idea that "reality is hierarchical and there's no downward causation" - in other words, we can always explain higher-level ideas in terms of lower-level ones
- Classical example: if we knew all the laws of physics, we could deduce what society will look like in 100 years
- This is a metaphysical/epistemological thesis that if only we knew the most basic laws of fundamental physics, we could predict and explain how everything else works: biology, economics, and so forth
- This sounds a little like what the logical empiricists thought about laws (true, testable statements that have "nomic necessity" (i.e. they're not "accidental" facts) and can be used in explanations)
- Sometimes a 3rd criterion is added here, saying that laws can be confirmed by a small number of positive instances (i.e. it becomes pointless to keep testing it after awhile, because it's a universal law!)
- After all, how many pieces of copper do you need to test before you figure out copper is a conductor?
- Here, we'd say these tests are "projectible" to general conclusions
- On the other hand, we'd hesitate to say you could quickly do this kind of induction with "accidental" facts (e.g. saying all sheep are white after just counting 50 or so)
- Many scientists hope that, one day, science will get to this point, where we can explain EVERYTHING with just a few basic laws
- Both of our readings today, though, challenge this idea
- Okay, on to Brandon's paper: "Does Biology Have Laws?"
- First off, look at figures 1 and 2 - why does Brandon reject the 1st one for the 2nd?
- Here, Brandon says that there are 2 dimensions to experiment types:
- You can have studies that are trying to prove hypotheses or just collect data
- You can manipulate the experiment, or just study it observationally without interfering
- Brandon
- Brandon also argued that in "evolutionary biology, more experimental is not always better;" why is that? And how does it relate to his claim that biology doesn't have "laws" in a logically empirical sense?
- For the first one, in biology a big concern is how things actually happen in nature, and if things in a laboratory are "too artificial," people might question if your results are how things actually work in the "real world"
- Brandon thinks that, unlike physics, biological phenomena aren't super projectible; the phenomena are more specific to given environments
- Part of this is because biology is FUNDAMENTALLY contingent, since we can imagine creatures having evolved in different ways, etc.
- Because of that, biology isn't inferior to physics, but it is DIFFERENT; physics is studying fundamental stuff, while biology is studying contingent stuff that could've happened in any number of ways
- In his words, these laws are "contingent," and can't be made fundamental
- The law of natural selection, for instance, is a law about probability, but we don't have any reason to think it'd hold if we traveled to a different planet where creatures never died out or something
- Therefore, Brandon thinks that biological "laws" fail the "nomic necessity" part of the logical empiricist's definition; it isn't necessary for aliens to have DNA or ribosomes or have genetic drift! Things could've happened differently!
- The only possible candidates for fundamental laws in biology are some of the probabilistic stuff, but again, those laws are probabilistic: they don't force anything on us!
- What does this mean for reductionism?
- Many people think it's at least problematic for it; if we can't describe how the laws work at one level, then this whole hierarchy starts to get wobbly
- That kinda-sorta bring us to Giere's paper, where he argues that science doesn't give us exact, universal laws, but models that more-or-less approximate how the real world works
- So, what lessons does Giere draw from looking at standard physics textbooks, and how are "models" central to his discussion?
- So, logical empiricists view theories as these axiomatic laws that we can "derive" things from
- However, Giere notes that in physics textbooks theories are NOT presented like this
- Instead, theories seemed to be viewed more as "approximate models" of how the real world works; Newton's 2nd law, for instance, describes how ideal particles behave if we ignore thermodynamics and friction and blah-blah-blah
- Under Giere's view, models aren't strictly "true" or "false;" they're just more or less similar to the real world
- Here, science is less a quest for the grand discovery of the universe's secrets and more a pragmatic attempt to get theories that are "good enough"
- This is definitely a rebuke against reductionism, too, because it's claiming that we can't get to exact, universal laws themselves! We're stuck just getting "close enough" - and we might get pretty close, but never all the way there
- Alright, go forth and do your homework! Goodbye!