Book contents
- Frontmatter
- Contents
- Acknowledgments
- Part I The Principle of Sufficient Reason and the Causal Principle
- Part II Objections to the PSR
- Part III Justifications of the PSR
- 11 Self-Evidence
- 12 Three Thomistic Arguments
- 13 Modal Arguments
- 14 Is the Universe Reasonable?
- 15 Explanation of Negative States of Affairs
- 16 The Puzzle of the Everyday Applicability of the PSR
- 17 Inference to the Best or Only Explanation
- 18 Inductive Skepticism
- 19 The Nature of Possibility
- 20 Conclusions
- Bibliography
- Index
13 - Modal Arguments
Published online by Cambridge University Press: 27 July 2009
- Frontmatter
- Contents
- Acknowledgments
- Part I The Principle of Sufficient Reason and the Causal Principle
- Part II Objections to the PSR
- Part III Justifications of the PSR
- 11 Self-Evidence
- 12 Three Thomistic Arguments
- 13 Modal Arguments
- 14 Is the Universe Reasonable?
- 15 Explanation of Negative States of Affairs
- 16 The Puzzle of the Everyday Applicability of the PSR
- 17 Inference to the Best or Only Explanation
- 18 Inductive Skepticism
- 19 The Nature of Possibility
- 20 Conclusions
- Bibliography
- Index
Summary
THE STRATEGY
One strategy for substantiating a principle is to start with a weaker and thus dialectically more acceptable principle, and then show that the weaker principle implies the stronger one or that the kind of intuitions that lead to the weaker one also lead to the stronger one. Nowhere has this strategy been as prominent as in ontological arguments for the existence of God. Instead of asking the atheist to accept that God exists, the ontological arguer asks the atheist to accept a prima facie weaker and more plausible claim, such as that possibly God exists or that we have a coherent concept of God. However, the theist has either previously defined God to be a being whose existence is necessary or in some way from which necessary existence provably follows. Therefore, the theist's interlocutor becomes committed to the claim that possibly necessarily God exists. But by the axiom S5 of modal logic, if possibly necessarily p (i.e., MLp), then necessarily p (i.e., Lp). Hence, necessarily God exists.
When formulated so baldly, the argument simply begs the question. Consider it written out:
(103) ML(God exists).
(104) Therefore, by S5, L(God exists).
It is a difficult problem to make precise the notion of “begging the question.” This example argument does not beg the question merely because it has only one nonlogical premise. After all, any valid argument with multiple premises can be replaced by one with a single conjunctive premise. The reason this ontological argument begs the question is subtler.
- Type
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- Information
- The Principle of Sufficient ReasonA Reassessment, pp. 231 - 248Publisher: Cambridge University PressPrint publication year: 2006