Logical Reasoning

PT139 · S4 · Q17 Because no other theory

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Because no other theory has been able to predict it so simply and accurately, the advance of the perihelion of Mercury is sometimes cited as evidence in support of Einstein's theory of general relativity.

Opposing Support

Because no other theory has been able to predict it so simply and accurately, the advance of the perihelion of Mercury is sometimes cited as evidence in support of Einstein’s theory of general relativity.

Evidence

This phenomenon was already well known when Einstein developed his theory.

He quite probably adjusted his equations to generate the correct numbers for the perihelion advance.

Conclusion

Therefore, accounting for this advance should not be counted as evidence in support of Einstein’s theory.

Evaluate

The argument assumes that if a theory is adjusted to account for a phenomenon, then the fact that the theory predicts that phenomenon should not be counted as evidence in support of that theory.

17.

Which one of the following principles, if valid, most helps to justify the argument above?

  1. Unless a phenomenon predicted by

    Wrong Conclusion

    This addresses whether Einstein’s theory should be credited with the discovery of the advance of the perihelion of Mercury, while the conclusion of the argument is about whether the prediction of the phenomenon should count as evidence in favor of Einstein’s theory.

    8% picked this

  2. A phenomenon that is predicted

    Wrong Premise

    This relationship would establish that if a theory was not developed with a phenomenon in mind, than that phenomenon should not count as evidence in favor of that theory. The evidence of this argument however, is that the theory was developed with the phenomenon in mind.

    3% picked this

  3. Unless a theory can accurately

    Wrong Premise / Wrong Conclusion

    This principle misrepresents the evidence and the conclusion of the argument. Not accounting for all relevant phenomena is different than accounting for a specific phenomenon (the advance of the perihelion of Mercury) and the theory not being well supported is different than a specific phenomenon not counting as support for the theory.

    2% picked this

  4. Correct

    If a theory is adjusted

    Why this is right

    This provides the link between Einstein’s theory likely being adjusted to account for the advance of the perihelion of Mercury with the conclusion that the predictions made by Einstein’s theory about that phenomenon should not be counted as evidence in support of Einstein’s theory.

    Skill tested: Principle-Strengthen · how this choice captures the argument's function is the move to repeat next time.

    69% picked this

  5. If a theory is adjusted

    Wrong Conclusion

    The conclusion of the argument is that the predictions made by Einstein’s theory about the advance of the perihelion of Mercury should not be counted as evidence in support of Einstein’s theory, while the conclusion asserted in this principle is that predictions should not be counted as predicting that phenomenon.

    19% picked this

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