The Biological Role of Pain and Pleasure
The argument from the biological role of pain and pleasure is an evidential argument from evil that focuses on a specific type of "natural evil": the biological role of pain and pleasure. Inspired by Hume and formulated by philosopher of religion Paul Draper, the argument uses Bayesian confirmation theory to argue for the hypothesis of indifference (i.e., metaphysical naturalism), a hypothesis that entails atheism. Draper's argument focuses on observations of humans and animals experiencing pain and pleasure. More specifically, Draper is interested in the following three observations:
- moral agents experiencing pain or pleasure we know to be biologically useful
- sentient beings that are not moral agents experiencing pain or pleasure that we know to be biologically useful
- sentient beings experiencing pain or pleasure that we do not know to be biologically useful
Draper's argument is that these observations are much more probable on the assumption that the hypothesis of indifference is true than on the assumption that theism is true. And therefore, observations of humans and animals experiencing pain and pleasure provide strong evidence for the hypothesis of indifference and against theism.
This brief summary doesn't do justice to the complexities of Draper's argument, but should be sufficient to give one an idea of what the argument is. A partial bibliography of this argument is given at the end of this page.
In this chapter, Paul Draper appeals to natural selection in order to show that the failure of many humans and animals to flourish is strong evidence against the existence of an omnipotent, omniscient, and morally perfect God. Treating theism and naturalism as hypotheses that aim to explain certain features of our world, Draper sets out to test each hypothesis against various known facts, including facts about human and animal suffering. After demonstrating that, prior to such testing, naturalism is more probable than theism in virtue of its smaller scope and greater simplicity, Draper goes on to argue that naturalism has far greater "predictive power" than theism, concluding that this provides strong grounds for rejecting theism.
Paul Draper argues that all else held equal, "naturalism is much more probable than theism," and therefore "theism is very probably false"; moreover, naturalism is simpler and smaller in scope than theism, and has much greater predictive power than theism with respect to evolutionary facts about suffering. In this response, Alvin Plantinga disputes that theism has larger scope than naturalism, and argues that what is really at issue for epistemic probability is not simplicity as Draper understands it (as "uniformity"), but "epistemic naturalness"--and that theism is more epistemically natural than naturalism. Moreover, if we treat theism as a hypothesis (rather than as a fact), theism might be subject to prima facie defeat by facts about suffering and misery, but nevertheless explain or predict a whole range of other data better than naturalism, such as our possession of reliable cognitive faculties, the existence of objective morality, the fine-tuning of the universe, the existence of abstract objects, and so on. But if some theists know that theism is true (in virtue of religious experiences, say), then their theism is not subject to defeat by facts about suffering even disregarding these explanatory advantages.
On the Plausibility of Naturalism and the Seriousness of the Argument from Evil (Great Debate) (2007) by Paul Draper
Alvin Plantinga does not challenge (and thus implicitly concedes) the soundness of Paul Draper's argument for the conclusion that certain facts about good and evil are strong evidence against theism. Plantinga does, however, challenge Draper's view that naturalism is more plausible than theism, which Draper needs to reach the further conclusion that, other evidence held equal, theism is very probably false. In addition, Plantinga challenges the significance of this final conclusion. In this chapter, Draper defends his views on plausibility and then argues that Plantinga's challenge to the significance of his final conclusion fails for two reasons. First, Plantinga fails to show that this further conclusion does not threaten the rationality or warrant of most theistic belief. Second, he mistakenly assumes that, in order to be significant, this conclusion must threaten the rationality or warrant of most theistic belief.
The first statement of Draper's argument was originally published in:
Paul Draper. "Pain and Pleasure: An Evidential Problem for Theists." Nous 23 (June, 1989), 331-350.
The essay has been subsequently reprinted in numerous anthologies, including The Evidential Argument from Evil, ed. Daniel Howard-Snyder (Indiana University Press, 1996).
It has also generated an enormous amount of discussion in the philosophical literature, including the following:
Criticized in Gregory E. Gannssle, "God and Evil," in The Rationality of Theism, ed. Paul Copan and Paul K. Moser (Routledge, 2003), pp. 259-277. See "Draper's Evidential Argument," pp. 265-274.
Criticized in Richard Otte, "Probability and Draper's Evidential Argument From Evil," forthcoming in Faith and Evil, ed. Peter van Inwagen (Eerdman's Publishers, 2004).
Criticized in Christopher Bernard, "Induction, Abduction, and the Argument From Evil," in God Matters: Readings in the Philosophy of Religion, ed. Raymond Martin and Christopher Bernard (Longman Publishers, 2003), pp. 323-338. See pp. 334-336.
Criticized in Richard Otte, "Evidential Arguments From Evil," International Journal for Philosophy of Religion 48 (2000), 1-10.
Criticized in Alvin Plantinga, Warranted Christian Belief (Oxford University Press, 2000). See "Draper's Argument," pp. 469-481.
Criticized in Loren Meierding, God, Relationships, and Evil (Writers Club Press, 2000). See Chapter 17, "The Indifference Hypothesis," pp. 399-423.
Criticized in William Alston, "Some (Temporarily) Final Thoughts on Evidential Arguments From Evil," in The Evidential Argument from Evil, ed. Daniel Howard-Snyder (Indiana University Press, 1996), pp. 311-332. See Section VII, pp. 327-330.
Criticized in Alvin Plantinga, "On Being Evidentially Challenged," in The Evidential Argument from Evil, ed. Daniel Howard-Snyder (Indiana University Press, 1996), pp. 244-261.
Criticized in William Alston, "Theism as Theory and the Problem of Evil," Topoi 14.2 (1995), 135-148. See Section V, pp. 145-147.
Defended in James F. Sennett, "Theism and Other Minds: On the Falsifiability of Non-theories," Topoi 14.2 (1995), 149-160. See Sections 4-7, pp. 154-159.
Criticized in Daniel Howard-Snyder, "Theism, the Hypothesis of Indifference, and the Biological Role of Pain and Pleasure," Faith and Philosophy 11 (1994), 452-466.
Criticized in Peter van Inwagen, "The Problem of Evil, the Problem of Air, and the Problem of Silence," in Philosophical Perspectives, 5, Philosophy of Religion, 1991, ed. James E. Tomberlin (Ridgeview Publishing Co., 1991).
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