LSAT (Law School Admission Test)Logical ReasoningMedium
A philosopher argues: 'Since it is impossible to definitively prove the existence of free will through empirical observation, we must conclude that free will does not exist.'
- AIt fails to consider that the absence of proof is not proof of absence.
- BIt ignores the possibility that free will exists but is simply beyond current scientific measurement.
- CIt does not define what 'free will' precisely means.
- DIt assumes that empirical observation is the only valid method for proving philosophical concepts.
Show answer & explanationAnswer & explanation
Correct answer: A. It fails to consider that the absence of proof is not proof of absence.
The philosopher commits an appeal to ignorance fallacy. The inability to *prove* something exists (or doesn't exist) does not logically mean it *doesn't* exist (or does exist). A lack of evidence is not evidence of absence.
Why the other options are wrong
- B. This is a consequence of the 'absence of proof is not proof of absence' principle. Option B articulates the general principle of the fallacy, which encompasses this specific possibility.
- C. While defining 'free will' is crucial in philosophical debate, the logical flaw in the argument's structure (lack of proof = non-existence) would remain even with a clear definition.
- D. The argument's flaw is not just about the method, but the conclusion drawn from the *failure* of that method. Even if empirical observation were the *only* method, the conclusion drawn from its failure would still be fallacious.
Appeal to Ignorance (Ad Ignorantiam)
A fallacy where a proposition is claimed to be true (or false) simply because it has not been proven false (or true).
- Lack of evidence against a claim is taken as evidence for the claim.
- Lack of evidence for a claim is taken as evidence against the claim.
- Often seen in arguments about things difficult or impossible to prove.
Memory trick: Don't omit the middle ground; other options can always be found!