Is it possible that a modus tollens argument can end in a fallacious conclusion?
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Original Question
So we're all on the same page:
Template
If P, then Q. Not Q. Therefore, Not P.
Argument
If Origin of Life scientists were actually going about it the correct way, then they would have outlined the synthetic chemical pathway to the cell. They haven't outlined the synthetic chemical pathway to the cell. Therefore, Origin of Life scientists are not going about it the correct way.
Comments on Question
It looks to me that If P, then Q means P implies Q, or If P is true, then necessarily, Q is true. (Hope I'm using the correct terms)
If Origin of Life scientists were actually going about it the correct way, then they would have outlined the synthetic chemical pathway to the cell.
Though the argument looks valid, the above proposition may well be false in the sense that, it is not the case that going about the correct way guarantees outlining the pathway to the cell.
This would be obvious in this proposition:
If I am a good person, then I have a lot of money.
I do not have money. Therefore, I am not a good person.
You might have also seen a line like this: if you are so smart, why are you not rich?
In other words, the premise is a conditional that may fail.
Answers
2To what others have said, I add the argument from ignorance (appeal to ignorance, argumentum ad ignorantiam) – assuming that a claim is true (or false) because it has not been proven false (true) or cannot be proven false (true).
Just some semantics; conclusions are true or false , not fallacious. Arguments can be valid or fallacious (invalid). I'm guessing you mean, "can a valid modus tollens argument produce a false conclusion?"
An argument is valid when, should the premises be true, the conclusion is implied.
E.g. If P, then Q. P, therefore Q. (Valid argument).
However, it could be possible for the premises to be false - e.g. it is not true that if P, then Q (either because P is not sufficient or some other reason). In that case, P would not imply Q, so P being true doesn't mean Q is true - and the argument would be invalid.
As for the conclusion, it might be true or false, but even if true, this new invalid argument wouldn't show it.
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Science is not If P, then Q. Not Q. Therefore, Not P. Rather I submit it is: If ~P, then ~Q sub "x"
This is a correct assertion with exception that it applies only to one specific study/case/whatever isolated in space/time. It is a universal quantifier error to apply it to all the work at once, since the scientific inquiry creates more hypotheses to test as it proceeds.
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Hypothesis
Test
Results → more Questions and the beat goes on.