03b. How to Argue - Induction & Abduction. Part 2/2.
Abduction doesn't reason straight from a premise to a conclusion, as we've seen in deduction and induction. Instead, it reasons by ruling out possible explanations until you're left with the most plausible one, given the evidence. Consider this:
Anna told you she failed her physics midterm.
Anna hasn't been in physics class since your teacher graded the exams. Anna has been in sociology class, which meets right after physics.
Anna dropped physics.
Now, with only these premises, we can't deductively or inductively prove our conclusion – that she dropped physics. But, it's a justifiable conclusion, because, given what we know, dropping the class is the most plausible explanation of events. We know she's not sick – because she's still going to sociology – and we know she had good reason to withdraw from the class, because she was unlikely to pass. Concluding that she dropped the course makes the most tidy use of our information, without leaving any loose ends. So let's look at another one: You and your roommate ate sushi last night.
You both wake up with violent stomachaches.
You and your roommate ate some bad sushi.
The mere fact that you're both sick doesn't prove that the sushi caused the sickness. But, given that you both ate the same thing and you both have the same symptoms – absent other information, like that a stomach virus is going around your dorm – the best explanation is that the sushi caused your intestinal anguish.
Now, like induction, abduction doesn't give us certainty. But it is a really useful way to get through puzzling situations when you don't have clear evidence from the past to help you out. Doctors use abduction a lot when they're diagnosing illnesses, and detectives of course use it when piecing together evidence. You probably use it pretty often too – just beware, because abduction must be used carefully! It uses only information you have at hand -- that's why doctors and detectives work so hard to dig up more data, and re-create events from the past, so they can help draw better conclusions. All right, now that we've looked at some argument types, let's find out how philosophers use arguments to interact with each other. Because, philosophers don't argue like other people do. It's not like the conversation you have around the dinner table about whether the Patriots are better than the Seahawks, or why plain M&Ms are superior to peanut, which is clearly a preposterous position to take. Philosophers hold each other to different, higher standards. They don't teach each other get away with saying, “I reject your argument because I don't like its conclusion.” Or, “That's preposterous, peanut M&Ms are so good.” Instead, if you disagree with a conclusion, you need to give reasons, just like the first person did when they made their case. Both people involved in this kind of exchange are known as interlocutors, because we have to name everything. The first one advances an argument, and the second one can either accept it, or offer a counterargument, which is just what it sounds like – an argument offered in opposition to another argument.
Think back to Socrates and the beard. You think Socrates had a beard, and your reasoning is that most men in his time and place had them. I, however, think you're wrong. So I give you a counterargument.
Gorgias, a contemporary of Socrates, said Socrates couldn't grow a beard and that he would sneak into barbershops and steal discarded clippings to fashion fake beards for himself. Therefore, Socrates didn't have a (real) beard. And I just want to point out that this is an actual philosophy conspiracy theory.
Gorgias was a real guy, who differed with Socrates on many things, and the dispute was said to have gotten personal.
According to accounts of the time, Gorgias actually spread the rumor that Socrates wore, like, a beard-wig, in an effort to shame and discredit his rival. I mean, how could you be a good thinker if you weren't a good beard-grower. Gorgias' gossip didn't go over well with everyone, and in this instance, let's say you are skeptical about it too. So you counter my counterargument with a counter-counterargument. Gorgias was known for being a gossip, and for hating Socrates, and trying to make him look bad. His fake beard tale seems wildly unlikely. Therefore, we can't take Gorgias' statement seriously, so we should fall back on the best information we have, which is that most of the men in his time and place had beards. And as you can see, arguments of different styles can be used in the same exchange.
Like, the original argument, about Socrates probably having a beard, was inductive. But this last counterargument is abductive. And that's fine. Arguments are meant to be useful, so we don't have to use the same kind of reasoning when we argue. This way of exchanging ideas through dialogue was popularized by Socrates, and so has become known as the Socratic method. Socrates thought dialogue was the best way to learn, and to get at truth. And it's important to note that, while philosophers have a reputation for being an argumentative lot, they don't think of the Socratic method as something that results in a winner and a loser. Rather, it's an exercise that brings both interlocutors closer to the truth. The goal of the philosopher is not to win, but to find truth, so you shouldn't be disappointed if someone presents a counterargument that you can't find a response to. When that happens, a good philosopher will be grateful to their interlocutor for helping them reject false beliefs and build stronger ones.
Today you learned about two more types of philosophical reasoning, induction and abduction. You've seen their strengths, and their weaknesses. And you've also learned about counterarguments, and the Socratic method. This episode is brought to you by Squarespace. Squarespace helps to create websites, blogs or online stores for you and your ideas. Websites look professionally designed regardless of skill level, no coding required. Try Squarespace at squarespace.com/crashcourse for a special offer.
Crash Course Philosophy is produced in association with PBS Digital Studios. You can head over to their channel to check out amazing shows like BrainCraft. It's OK To Be Smart, and PBS Idea Channel. This episode was filmed in the Doctor Cheryl C. Kinney Crash Course Studio with the help of these amazing people and our Graphics Team is Thought Cafe.
