The “inductivist turkey” and Thanksgiving: why we should not rely on our experience

This is a sad story. This story talks about a turkey. Yes, I am talking about the turkey that some of you are going to eat for Thanksgiving. I’m talking about the “inductivist turkey”. This is a quite old story and many philosophers of science have been written about it for years, perhaps for their lack of jokes, who knows?

This metaphor, this is the right way to call it, was invented by the famous logician Bertrand Russel and re-formulated from Carl Popper afterward:

This turkey found that, on his first morning at the turkey farm, he was fed at 9 a.m. However, being a good inductivist, he did not jump to conclusions. He waited until he had collected a large number of observations of the fact that he was fed at 9 a.m., and he made these observations under a wide variety of circumstances, on Wednesdays and Thursdays, on warm days and cold days, on rainy days and dry days. Each day, he added another observation statement to his list. Finally, his inductivist conscience was satisfied and he carried out an inductive inference to conclude, “I am always fed at 9 a.m.”. Alas, this conclusion was shown to be false in no uncertain manner when, on Christmas eve, instead of being fed, he had his throat cut. An inductive inference with true premises has led to a false conclusion. (via Alan Chalmers, What is this thing called Science, 2nd edition, University of Queensland Press, St. Lucia, 1982)

The induction is a form of reasoning that starts from the examination of a number of specific cases and leads to a universal conclusion. For example, a number of findings such as “this tracking time tool is boring, this second time tracking tool looks to complex, this third time tracking tool is not helping me with my time management, etc…” it will naturally bring to this assumption “all time tracking tools are boring, too complex and unnecessary.” As we can see the induction proceeds from single data according to the scheme: some → all.

However, in an induction, the truth of the premises (although they are many) never guarantees the truth of the conclusion and outcome: one counterexample (an unexpectedly simple and easy-to-use time tracking software) drops the conclusion of an induction.
In our everyday life, however, we constantly rely on inductions. They provide us predictions about the outcomes of our actions and interactions that we have with the environment around us. With no inductions, our world would be chaotic as we would have no reason to believe that the future is similar to the past. Every change in this regularity we are used to would raise many doubts.

Are inductions always true?

Once the philosopher Karl Popper read this story, he immediately argued that the truth of universal statements it is not logically justified through the truth of single propositions, as many these are: any conclusions obtained in this way can always be false.

So what is the Popper’s proposal? His idea is that, once admitted there are no inductive procedures that make it possible to establish the truth of hypotheses and theories, the pretense of being able to attribute to scientific claims a truth should be dropped.

Science is not empirically verifiable.

In fact, no matter how great the number of singular statements at our disposal is, these cannot verify universal statements, while just one singular statement can falsify.

All swans are white, right? Or maybe, not…

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About Giovanni

Giovanni's recently taken up a "caffeine free" way or life relying on green shakes in the morning (not sure he can still be considered Italian). Loves kayaking and always hopes on rainy days.