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Logical fallacies and the environment: circular reasoning

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circular-reasoning

Circular reasoning is a form of chicken-and-egg argument, where what needs to be proven is what one starts with.  It is not a formal logical fallacy since all the statements may well be true and not contradict one another; but it is a fallacy in the sense that the statements cannot be used as a proof of one another.

For instance, a classic example of circular reasoning comes from religion: the pope is infallible, because the pope said so.  If you are a devout catholic, you may accept these two statements.  However, logic says that using “because” is an error – there is no cause or proof that link these two.  (Incidentally, what if the pope, being infallible, said that the pope is no longer infallible? This creates a version of the Liar’s Paradox – see below.)

Circular reasoning occurs relatively rarely in environmental and scientific debates.  However, accusations of circular reasoning are remarkably frequent.  Most often, it is groups who oppose the scientific consensus who accuse scientists of circular reasoning.  Consider the cartoon below:

begging creation

New fossils are indeed quickly dated using the age of the rock where they are found.  And rocks can also use embedded fossils as an indication of the age of the rock.  But it isn’t a chicken and egg situation, as implied in the cartoon above, because the age of rocks, which is the original reference, is first estimated using other techniques: historical rates of sedimentation, atomic clocks, etc.

Accepting the science behind climate change is often described as being circular reasoning by deniers.  For instance, here’s a text by Tim Ball:

Through the Intergovernmental Panel on Climate Change (IPCC) they produced the science required to support their claim. It is a well-thought out, well-planned, classic circular argument.

More succinctly, they created the problem, created the proof of the problem, then offered the solution. This is what was done with the AGW claim. They assumed, incorrectly, that a CO2 increase causes a temperature increase. They then provided proof by programming computer models in which a CO2 increase caused a temperature increase. They ran the model(s) by doubling CO2, ceteris paribus. The results showed a temperature increase, which proved their claim

How do we know that this accusation of circular reasoning is wrong?  First, there is the fact that the IPCC is a summary of scientific consensus as existed before the creation of the first IPCC.  Then Ball says that assuming an increase in CO2 causes warming (AGW: anthropogenic global warming) is incorrect.  But this is not an assumption; this has been verified in numerous occasions, in the lab, as well as in astronomic observations: Venus is much warmer than expected based on the distance to the sun, and that is due to its CO2 rich atmosphere.  Most importantly, the models that Ball is referring to are not used as a way to prove that climate change is true; they are used as a way to estimate possible consequences of increasing CO2.   If a claim of causality was made, then yes, this could be circular reasoning, but no such claim is made.  (The only claim made is that observed climate change demonstrates that the models do a decent job of representing the physical reality).

So, contrary to what Ball claims, there is no circular reasoning.  However, this is a tactic commonly used: claim that the opposite party is making a claim of causality when none exists, and then accuse them of circular reasoning.  This is actually setting up a straw man, which Ball does transparently and clumsily (he is not among the more eloquents of the deniers).

Notes: a synonym for circular reasoning is begging the question.  This is an unfortunate expression allegedly based on a mistranslation of the original latin for “assuming the first point.”  It does not mean inviting a question.  The Liar’s Paradox is classically stated as follows: “All Cretans are liars. Believe me: I’m a Cretan.”  This set of statements is self-contradictory, but, as with circular reasoning, neither statement can be used to demonstrate the truth of the other.

begging rat

Note: As instructors we’re expected to instill in our students critical thinking abilities. So this semester I included in my Environmental Issues class a review of some common logical fallacies with examples taken from the environmental scene. Much to my surprise, I couldn’t find such a collection through a Google search. So I started crafting my own by collecting examples of logical fallacies that occur in environmental news and discussions. Previous post in the series: hasty generalization and the ecological fallacy.

 

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Written by enviropaul

April 10, 2016 at 4:39 pm

One Response

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  1. […] Note: As instructors we’re expected to instill in our students critical thinking abilities. So this semester I included in my Environmental Issues class a review of some common logical fallacies with examples taken from the environmental scene. Much to my surprise, I couldn’t find such a collection through a Google search. So I started crafting my own by collecting examples of logical fallacies that occur in environmental news and discussions. This is the last post in this series (for a while!).  The previous post was on circular reasoning. […]


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