Online research in philosophy

The fundamental constants that are involved in the laws of physics which describe our universe are finely tuned for life, in the sense that if some of the constants had slightly different values life could not exist. Some people hold that this provides evidence for the existence of God. I will present a probabilistic version of this fine-tuning argument which is stronger than all other versions in the literature. Nevertheless, I will show that one can have reasonable opinions such that the fine-tuning argument doesn't lead to an increase in one's probability for the existence of God. The fine-tuning argument Objective versus subjective probability Observational selection effects The problem of old evidence Against the fine-tuning argument Many universes.

Recent discussion of the problem of evil has centered around what is known as the probabilistic or evidential argument from evil. According to this argument the evil in our world is evidence against the existence of God, even though evil is logically consistent with God’s existing. Based on this it is claimed it is irrational to believe one of the traditional theistic religions, unless there is overwhelming positive evidence to counter this negative evidence. One of the most important and widely discussed versions of this argument is due to Paul Draper.1 In this paper I will look at Draper’s argument and argue that he has made a simple fundamental error; as a result his argument is irrelevant to most theists. After discussing this error in Draper’s argument, I will discuss probabilistic arguments from evil from the perspective of confirmation theory. The error in Draper’s argument is easily made and could occur in any probabilistic argument from evil; looking at confirmation theory and probabilistic arguments from evil will provide insight into reasoning about evil and belief in God.

The Fine-Tuning Argument (FTA) is a variant of the Design Argument for the existence of God. In this paper the evidence of fine-tuning is explained and the Fine-Tuning Design Argument for God is presented. Then two objections are covered. The first objection is that fine-tuning can be explained in terms of the existence of multiple universes (the 'multiverse') plus the operation of the anthropic principle. The second objection is the 'normalizability problem'– the objection that the Fine-Tuning Argument fails because fine-tuning is not actually improbable.

The fine-tuning argument can be used to support the Many Universe hypothesis. The Inverse Gambler’s Fallacy objection seeks to undercut the support for the Many Universe hypothesis. The objection is that although the evidence that there is life somewhere confirms Many Universes, the specific evidence that there is life in this universe does not. I will argue that the Inverse Gambler’s Fallacy is not committed by the fine-tuning argument. The key issue is the procedure by which the universe with life is selected for observation. Once we take account of the procedure, we find that the support for the Many Universe hypothesis remains.

The fine-tuning argument can be used to support the Many Universe hypothesis. The Inverse Gambler’s Fallacy objection seeks to undercut the support for the Many Universe hypothesis. The objection is that although the evidence that there is life somewhere confirms Many Universes, the specific evidence that there is life in this universe does not. I will argue that the Inverse Gambler’s Fallacy is not committed by the fine-tuning argument. The key issue is the procedure by which the universe with life is selected for observation. Once we take account of the procedure, we find that the support for the Many Universe hypothesis remains.

It is shown that, for certain classes of cosmological model which either postulate or give rise to infinitely many universes, only a measure zero subset of the set of possible universes above a given size can in fact be physically realized. It follows that claims to explain the fine tuning of our universe on the basis of such models by appeal to the existence of all possible universes fail.

In recent years, several philosophers have offered reasons for thinking that if theism is true, the actual world (likely) includes multiple universes. Some have further argued that a multiverse model can help theists respond to arguments from evil. The latter move has been criticized in various ways. In a forthcoming paper in THIS JOURNAL, Jason Megill offers a novel and ambitious meta-argument: he claims that the bare epistemic possibility of multiple universes defeats all arguments from evil. If Megill’s argument were sound, this would be an enormously important result in the philosophy of religion. The problem of evil, after all, is widely thought to be one of the most serious objections to theism. It has been discussed throughout the history of philosophy, and has generated an enormous and very technical contemporary literature. But can the bare epistemic possibility of multiple universes really defeat all arguments from evil, both past and present, as Megill maintains? In what follows, I contend that Megill fails to establish premise a crucial premise in his argument. I conclude with a rival account of the effect of multiverse models of theism on the debate about evil.

Many theists regard the claim that certain fundamental constants of nature are fine-tuned for life as the best scientific argument for the existence of God since Paley’s watch. Even atheist physicists find these so-called “anthropic coincidences” difficult to explain naturally and many think they need to invoke multiple universes and the so-called “anthropic principle” to do so. Certainly if there are many universes, fine-tuning is simple. Our universe is not fine-tuned for life. Life is fine-tuned to our universe. While multiple universes are expected from modern cosmological theories, theists and some scientists object that invoking the unobservable is not science. Of course, God is unobservable too, so the best theists can claim is a standoff.

Bayesian conceptions of evidence have been invoked in recent arguments regarding the existence of God, the hypothesis of multiple physical universes, and the Doomsday Argument. Philosophers writing on these topics often claim that, given a Bayesian account of evidence, our existence or something entailed by our existence (perhaps in conjunction with some background knowledge or assumption) may serve as evidence for each of us. In this paper, I argue that this widespread view is mistaken. The mere fact of one's existence qua conscious creature cannot serve as evidence on the standard Bayesian conception of evidence because knowledge of one's existence is a necessary part of the background knowledge relative to which all epistemic probabilities are defined. It follows that some formulations of the fine-tuning argument (for theism or a multiverse), the argument from consciousness (for theism) and a rejoinder to the Doomsday argument are mistaken.

In this article I examine a common objection to the fine-tuning argument (an objection which may be referred to as the atheistic many universes (AMU) objection). A reply to this objection due to Roger White has been the subject of much controversy; White's reply has been criticized by Rodney Holder, on the one hand, and Neil Manson and Michael Thrush on the other. In this paper I analyze Holder's work in an effort to determine whether the AMU objection successfully defeats the fine-tuning argument. I conclude that the fine-tuning argument can be reformulated so as to avoid the AMU objection.