Can Science Test Supernatural Worldviews?

Abstract

Several prominent scientists, philosophers, and scientific institutions have argued that science cannot test supernatural worldviews on the grounds that (1) science presupposes a naturalistic worldview (Naturalism) or that (2) claims involving supernatural phenomena are inherently beyond the scope of scientific investigation. The present paper argues that these assumptions are questionable and that indeed science can test supernatural claims. While scientific evidence may ultimately support a naturalistic worldview, science does not presuppose Naturalism as an a priori commitment, and supernatural claims are amenable to scientific evaluation. This conclusion challenges the rationale behind a recent judicial ruling in the United States concerning the teaching of “Intelligent Design” in public schools as an alternative to evolution and the official statements of two major scientific institutions that exert a substantial influence on science educational policies in the United States. Given that science does have implications concerning the probable truth of supernatural worldviews, claims should not be excluded a priori from science education simply because they might be characterized as supernatural, paranormal, or religious. Rather, claims should be excluded from science education when the evidence does not support them, regardless of whether they are designated as ‘natural’ or ‘supernatural’.

Appendix: Testing God: A Bayesian Approach

A believing Christian amputee prays to the Christian God for re-growth of his arm:

1.1 Hypotheses:

God exists = +H

God does not exist = −H

Assume equal prior probabilities for H and −H: P(+H) = 0.5; P(−H) = 0.5

1.2 Evidence:

Amputee’s arm grows back after prayer = +E

Amputee’s arm does not grow back after prayer = −E

$$ {\text{P}}( + {\text{E}}\left| { + {\text{H}}} \right.) = 0.9 $$

If God exists, there is a 9/10 chance that the amputee’s prayers will be answered- this is based on the passage in the King James Bible: “And all things, whatsoever ye shall ask in prayer, believing, ye shall receive.” Matt 21:22). P(+E|+H) is set equal to 0.9 (a high probability) instead of 1.0 to leave open the possibility that the amputee failed to utter the prayer perfectly or that the amputee’s faith, although he is an avowed and devout believer, is not sufficient to merit God’s beneficence

$$ {\text{P}}( + {\text{E}}\left| { - {\text{H}}} \right.) = .00001 $$

If God does not exist, there is a 1/100,000 chance that the amputee’s arm will grow back naturally. This is empirically a grossly over-optimistic estimate, since there have been many times 100,000 amputees, all of which have failed to have their limb grow back; But we don’t set it to zero because there is always a possibility that there is something we don’t know about how nature operates. Further, it is possible that, within the lifetime of this particular amputee, medical science will discover a way to cause the arm to re-grow through natural means.

$$ {\text{P}}( + {\text{H}}\left| { + {\text{E}}} \right.) = {\text{P}}( + {\text{E}}\left| { + {\text{H}}} \right.)*{\text{P}}({\text{H}})/[{\text{P}}( + {\text{E}}/ + {\text{H}})*{\text{P}}({\text{H}}) + {\text{P}}( + {\text{E}}\left| { - {\text{H}}} \right.)*{\text{P}}( - {\text{H}})] $$

(Bayes’ Theorem)

$$ {\text{P}}( + {\text{H}}\left| { + {\text{E}}} \right.) = 0.9*0.5/(0.9*0.5 + .00001*.5) = .45/(.45 + .000005) \sim 1.0 $$

$$ {\text{P}}( + {\text{H}}\left| { - {\text{E}}} \right.) = 0.1*0.5/(0.1*0.5 + 0.99999*.5) = .05/(.05 + .499995) \sim .09 $$

$$ {\text{P}}( + {\text{H}}\left| { + {\text{E}}} \right.) > {\text{P}}( + {\text{H}}) $$

(i.e., the posterior probability of +H, given +E, is greater than the prior probability of +H.)

$$ {\text{P}}( + {\text{H}}\left| { - {\text{E}}} \right.) < {\text{P}}( + {\text{H}}) $$

(i.e., the posterior probability of +H, given −E, is less than the prior probability of +H.)

Therefore, the hypothesis that the Christian God exists, H, is confirmed by evidence, E, and is disconfirmed by evidence, −E.

Hence, the fact that no devout Christian amputees have ever had their limbs grow back following prayers to the Christian God requesting limb re-growth is strong evidence that the Christian God does not exist.

(The example presented above is inspired by the website: http://whywontgodhealamputees.com/)