Blind Chance versus Block Universe? Dawkins’s famous thesis stating that “Darwin made it possible to be an intellectually fulfilled atheist” has become a quasi‐synonym for the (alleged) incompatibility of evolutionary biology and theism (Dawkins 2006b, 6). Evolutionary theory has been claimed to make the God hypothesis not only dispensable, but also untenable­—insofar it contradicts natural science.

For the atheist argument to work, interpreting probability statements of evolutionary theory in terms of pure chance seems to be crucial. ³ However, if the origin and development of life is nothing but a series of undirected random processes, it is simply meaningless to speak of creative acts of God; chance excludes purpose by definition. Therefore, the creation hypothesis could be saved if evolutionary probabilities were interpreted in a pure epistemological sense. According to this interpretation, uncertainty of theoretical predictions is exclusively due to our ignorance, and has nothing to do with nature; probability statements of evolutionary theory reflect solely lack of knowledge, while in reality natural processes are completely determined and occur out of necessity. There is no doubt that such a probability interpretation is compatible with the creation hypothesis, in so far in determining the physical properties of our universe, God creates conditions which are necessary for life to evolve. Moreover, in a deterministic world the God‐given set of initial conditions, physical parameters, and natural laws lead to the result intended by God with certainty; nothing is left to chance eventually causing unwelcome surprises. However, there is a price to pay for reconciling evolutionary theory with the creation hypothesis this way: the problem of evil arises in a more acute form. If the universe is completely deterministic, everything occurs because God wants it. To put it in Kenneth Miller's words:

When a stray bullet is randomly fired into a crowd, God decides who will get hit, and who will survive. When the biggest hurricane of the year hits Key West and not Miami, it had to be God's will. You could, I suppose, cast the Almighty in this guise, make Him a cosmic tyrant, a grand puppeteer pulling every string at once, and then nothing would be left to chance. (Miller 2002, 234)

If the factual degree of pain and evil sentient organisms suffer from, or inflict upon one another is the creator's will, then this being cannot be the morally perfect God of theism, and such a person is hardly worth being worshipped by the creatures.

To sum up, in confronting the God hypothesis with evolutionary theory, theism is left with the following dilemma: either a probability interpretation in terms of blind and undirected chance is correct, or the proper interpretation is an epistemic one. Obviously, theism is incompatible with both options, since the first option makes the very idea of creation, in particular the doctrine of creatio continua, obsolete, while the second option implies a more acute form of the problem of evil. In face of this, is there really a choice to be made between theism and evolutionary theory?

Why Take the Problem Seriously? Of course, one could conveniently dissolve the dilemma by declaring such incompatibilities completely unproblematic. Such incompatibilities become problematic only if we commit ourselves to the idea of objective and universal truth inseparably connected with the law of noncontradiction. Abandoning realism and redefining truth in terms of postmodern relativism, on the other hand, dispenses one from being bounded by logical rules.

Yet, giving up the universality of the law of noncontradiction implies the loss of meaning and intelligibility. ⁴ It follows that theological statements can at best serve as expression of emotions or volitions when giving up the law of noncontradiction.

Assuming that theological statements are meaningful and truth‐relevant statements, theism faces the task of demonstrating that probability statements of evolutionary theory need neither be interpreted in an epistemological sense, nor are the same probability statements to be interpreted in terms of blind chance or arbitrariness. Finally, it has to be shown that there is a third option of interpreting probability statements of evolutionary theory which is compatible with the creation hypothesis without sharpening the problem of evil. In short, theism should offer a third option besides blind Darwinian chance and pure Laplacian determinism.

Perspectives for Theistic Evolution In the field of science and religion, a good deal of important work has already been done to reconcile evolutionary dynamics with the creation hypothesis. In studying the subtle and complex interplay of random mutations in the DNA and their (more or less) deterministic selection through the environment, which are (allegedly) causally independent, most approaches focus on the latter and follow a sort of “top‐down strategy,” aiming to show how necessity (or law‐likeness) brings order into chaos arising due to randomness.

Thereby, we can basically distinguish two main lines of argumentation, the biologist's manner and the physicist's manner. As indicated by its name, the biologist argues for order arising due to natural forces in purely biological terms. Here, one of the most important contemporary approaches might be the theistic interpretation of convergent evolution, as defended by British paleontologist Simon Conway Morris. He advances the (among biologists widely accepted) view that given similar environments, different organisms arrive at the same function through different evolutionary pathways, or to put it with Conway Morris, evolutionary convergence is “the recurrent tendency of biological organization to arrive at the same ‘solution’ to a particular ‘need’” (Conway Morris 2003, xii). Yet, from this fact Conway Morris infers that the emergence of intelligent life is nearly inevitable—a result which need not, but can be interpreted in terms of Creation. On the other hand, one can argue for understanding the interplay of chance and necessity within evolutionary dynamics from a physics point of view; in most cases, that means arguing in terms of nonlinear dynamics. Simply put, the theistic argument is based on the fact that emergent features of complex physical systems constrain the random behavior of their constituents. Note, however, that the adjective “random” is used here to characterize the great instability associated with chaotic systems—a property which is a direct result of nonlinearity allowing for evolution from nearly identical states to extremely dissimilar ones. “In fact, it is randomness constrained by deterministic correlations that is critical for producing the structures we perceive as ‘complex’” (Young 1996, 238). Most famously, John Polkinghorne and Arthur Peacocke referred to the behavior of chaotic systems to demonstrate that evolutionary chance does not rule out Creation; rather, it manifests the creativity with and through which God acts in the world, without completely determining it. ⁵ While most theistic interpretations of evolutionary dynamics prefer the top‐down strategy (starting with the law‐like environmental selection), little attention has been paid to possible bottom‐up solutions (starting with random mutations) which are otherwise not unpopular in the field of science and religion. ⁶ In what follows, I shall address the question if and to what extent such a model can contribute to reconciling evolutionary theory with the creation hypothesis. In particular, I ask if the bottom‐up model I suggest can be considered a complementary account to top‐down approaches.

Condition 1: Quantum Indeterminism In light of classical physics, there is every reason to believe that the world is deterministic ⁹ ; the temporal evolution of physical systems can be completely described by the Newtonian equations of motion and the given initial conditions so that the state of a physical system S at any time t can be uniquely derived from the state S₀ at an arbitrarily chosen time t₀. In quantum mechanics, contrarily, the physical state of a system can be given only in terms of probability statements, that is, generally without certainty.

Whether the probabilistic nature of quantum mechanics implies ontological indeterminism has been conversely discussed since the foundations of the theory were laid. This question forms a part of the so‐called interpretation debate that is struggling with the question as to how to properly understand what quantum mechanics tells us about reality. At the moment, no suggestion is (commonly) considered to provide a definite solution to the interpretational problems. Accordingly, a finite decision in favor of quantum indeterminism cannot be made. Yet, I will show that by considering conceptual issues, there is a good case to be made that quantum mechanics implies ontological indeterminism. That is to say, I will argue that interpreting quantum probabilities in terms of ontological indeterminism is at least as plausible as other interpretations and that each of the other views either has difficulties with self‐consistency or leaves the determinism‐indeterminism question open.

Metaphysical Determinism versus Principle of Predictability In discussing determinism in the context of science, it is essential to distinguish between the metaphysical concept of determinism and an empirically testable necessary condition for the metaphysical concept, namely, the principle of predictability.

Obviously, the metaphysical concept of determinism stating that every event in the world is completely determined by other (antecedent) events so that same initial conditions always bring about the same events is an empirically untestable philosophical hypothesis; nothing could prevent a hard determinist from believing that it is just the manifestation of ignorance when an event appears to be caused by chance, while the underlying physical processes are unambiguously fixed.

An empirically testable necessary condition for determinism to be true provides the principle of predictability. Instead of a priori preferring a metaphysical position, by referring to the degree of precision a prediction can be made with we obtain an empirical argument for or against determinism: If within a physical theory every future event can be predicted with certainty, the theory can be considered an evidence for determinism. If, on the other hand, there are at least some future events the physical theory cannot predict with certainty, the theory can be considered an evidence against determinism.

In summary, the metaphysical concept of determinism tells the universe how to work, while in applying the principle of predictability, we simply ask the universe how it works (see Table 1).

Is Quantum Mechanics Really Indeterministic? By applying the principle of predictability to quantum mechanics, the question of quantum indeterminism appears to be a fairly easy one to answer. As within quantum mechanics an event is always predicted in terms of probability statements, quantum mechanics does not meet the predictability criterion for determinism that requires predictions with certainty, and therefore quantum indeterminism is to be preferred. However, this argument counts as a rather weak one. The reason for rejecting the principle of predictability as an appropriate criterion for quantum indeterminism may lie in the metaphysical character of determinism, in so far a philosophical belief can always be considered true, so that in case of conflict with science the scientific theory will be rejected. Yet it is highly questionable to maintain determinism at the expense of rejecting quantum mechanics representing an empirically extremely well‐confirmed scientific theory. Another reason for not accepting the principle of predictability in the context of quantum mechanics is that it does not apply if probability statements need necessarily be interpreted in an epistemological sense. In fact, to argue in this manner is the strategy of most opponents of quantum indeterminism. Therefore, in order to argue for quantum indeterminism, one must show that this is not the case, that is, quantum probabilities need not necessarily be interpreted in an epistemological sense. In what follows, I will do this by reasoning that deterministic interpretations of quantum formalism are far from being compelling.

There are two serious deterministic interpretations of quantum mechanics: many‐worlds theory and Bohmian mechanics. Many‐worlds theory aims to deduce Born's probability rule from the (allegedly) deterministic Schrödinger equation by assuming the existence of innumerable worlds coming into being in order to realize each possible state predicted by the Schrödinger equation. ¹⁰ Bohmian mechanics takes the other, less spectacular way and introduces an additional equation making quantum formalism deterministic. This guiding equation guarantees that a particle always has a well‐defined position and trajectory in the 3‐dimensional physical space, even though probabilities nevertheless arise because of ignorance of the initial positions that cannot, in principle, be overcome.

The judgment of both theories is not uniform. While many‐worlds theory is quite popular, Bohmian mechanics is considered weird among most physicists. Regardless of this, I will now argue that many‐worlds theory has difficulties with self‐consistency while Bohmian mechanics is formally consistent, but leaves the determinism‐indeterminism question open. ¹¹ The meaning of probabilities in the framework of many‐worlds theory is, to put it mildly, not clear; any probability not equal to one or to zero is just meaningless, because a certain event E either occurs in a world coming into being for this ground, that is, P(E) = 1, or E is no solution of the Schrödinger equation, and therefore does not occur at all, that is, P(E) = 0. ¹² “The moral is that it is impossible to get the right answer for probabilities without adding something to the theory” (Barrett 2003).

Adding something to the theory would, however, contradict its main aim not to presuppose anything but the Schrödinger equation. In Bohmian mechanics, interpreting probabilities is a more subtle issue. A proper probability interpretation must be compatible with the claim that at each point of time each particle has—just as in classical physics—both a definite position and a definite momentum. Thus, naturally (and this is indeed the most common understanding among Bohmians), Bohmian probabilities are considered long run relative frequencies. Thereby, the relative frequency of an outcome is the occurrence of the relevant outcome divided by the total number of observations. For example, if you toss a coin ten times and get heads seven times, the relative frequency of getting heads is 0.7. Increasing the number of tosses, you should get (approximately) as many heads as tails so that the relative frequency of heads becomes 0.5; but can you thus infer that the probability of getting heads is 0.5? By affirming this question, you consider probabilities as long run relative frequencies. Clearly, (if consistent) a relative frequency interpretation preserves determinism. More exactly, it works only if determinism is true. Yet its consistency depends on whether relative frequencies can in fact be transferred into probabilities. In order to justify their interpretation, advocates of the relative frequency interpretation refer to a mathematical theorem, the Law of Large Numbers (LLN), which defines the (formal) relation between relative frequencies and probabilities. Interpreting probabilities in terms of relative frequencies fails, however. Since, to put it with U.S. philosopher Craig Callender, LLN solely states that “probability is close to long run relative frequency, probably. Clearly, the second use of probability needs a non‐probabilistic explication to avoid circularity.” ¹³ In other words, LLN cannot provide a probability interpretation in terms of relative frequencies, insofar as LLN itself is in need of a probability interpretation. In consequence, the only possibility to preserve determinism is an interpretation of probabilities by way of the wave function which—in the framework of Bohmian mechanics—not only “guides” each particle to follow a well‐defined trajectory, but also defines the probability distribution of the particle's position. Obviously, in favor of a realist interpretation which is a necessary condition for determinism, the wave function itself has to correspond to an element of reality. In fact, the Bohmian wave function is often considered as representing a real physical field. However, this interpretation leads to difficulties; in order to describe a many‐particle system containing n particles we need to write its wave function in a 3n‐dimensional phase space. Moreover, it is unclear what the ontological relation of the wave function to its particle is. Does the particle “produce” its wave function the same way an electron produces the electromagnetic field around itself, or vice versa? Either way, for a realistic interpretation of the wave function one has to accept a quite strange metaphysical assumption. On the other hand, interpreting the guiding wave function with the help of irreducible dispositions of the particle to move in a particular direction given its position and the external forces makes such a weird metaphysical hypothesis like a 3n‐dimensional field for each particle dispensable. ¹⁴ Therefore, it is safe to say that Bohmian mechanics does not just leave the question open if quantum mechanics is deterministic, but its deterministic interpretation comes with a more burdensome metaphysical price tag.

In summary, neither the many‐worlds theory nor Bohmian mechanics provide a no‐go argument for interpreting quantum probabilities in terms of indeterminism. Rather, it seems that deterministic interpretations fail mainly because the metaphysical concept of determinism is considered a necessary overall context for quantum formalism. However, as long as there is no compelling interpretation of quantum mechanics in terms of determinism, applying the principle of predictability in order to argue for (ontological) indeterminism cannot be regarded inappropriate.

Condition 2: No Randomness The fact that there is no compelling deterministic interpretation of quantum theory allows for applying the principle of predictability. Since in quantum formalism predictions can usually be made only in terms of probabilities (≠ 0, 1), quantum theory yields an empirical argument for ontological indeterminisim. However, quantum indeterminism can be fruitfully embedded in a theistic context only if quantum probabilities reflect open‐endedness or creaturely creativity instead of blind, undirected chance incompatible with divine love.

In this context, the most significant approach is a probability interpretation in terms of so‐called single case propensities. Thereby, propensities are regarded dispositional properties of physical systems, that is, categorically irreducible features of these systems. In certain situations, the propensities become actualized which is manifested by probabilities being objective features of these situations. Clearly, in the framework of propensity interpretations, probabilities do not reveal randomness or undirected chance. On the contrary, probabilities are considered to reveal the irreducibility of the first‐person perspective in nature, manifesting creaturely creativity. To put it another way, if there are alternate possibilities in a given situation, the reason for realizing any of these possibilities lies within the system itself so that it can only be objectified in terms of probabilities, and cannot be translated into a fully deterministic third‐person description. This means that in the framework of single‐case propensity interpretations probabilities (≠ 0, 1) reveal both the existence of alternate possibilities in a concrete situation and the existence of dispositional properties of the corresponding physical system.

Although propensity interpretations of quantum probabilities have often been criticized, there seems to be no reason not to regard them as serious candidates for interpreting quantum probabilities. First, the critiques are mostly concerned with technical aspects, and recent (re‐)formulations seem to overcome the old problems. ¹⁵ Second, there is no commonly accepted epistemic interpretation of quantum probabilities: as we have seen, deterministic concepts mostly fail to track probabilities back to ignorance or lack of knowledge. The possibility of interpreting probabilities in an ontological, yet nonrandom sense shows, on the other hand, that quantum indeterminism is not necessarily identical with pure chance or undirected random behavior.