B: The Relevant Background Information

1. Living things, including sentient beings, exist.
2. In order to flourish, living things need an adequate supply of food and water, are able to reproduce, avoid predators, and remain healthy.
3. All living things are in competition for limited resources.

E: The Evidence to be Explained

Let E be observations of the flourishing and languishing of sentient beings. E can be broken down into three specific observations:

E1: Only a fraction of living things, including the majority of sentient beings, thrive. In other words, very few living things have an adequate supply of food and water, are able to reproduce, avoid predators, and remain healthy.
E2: An even smaller fraction of organisms thrive for most of their lives.
E3: Almost no organisms thrive for all of their lives.

Hypotheses (Core and Auxiliary Hypotheses)

Core, rival hypotheses:
T: classical theism
N: metaphysical naturalism

Auxiliary hypothesis:
D: Darwinism: the theory that natural selection operating (indirectly) on random genetic mutation is the principal mechanism driving the evolutionary change that results in increased complexity

The Argument Formulated

Let “>!” mean “is much greater than”

(1) Therefore, Pr(E | B & D & N) >! Pr(E | B & D & T).
(2) E is known to be true.
(3) T is not much more probably intrinsically than N.
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(4) Therefore, other evidence held equal, T is probably false.

Defense of (1)

N entails that living things, if they exist, are not the result of actions performed by any supernatural person, including God. Thus, on N, the moral difference between flourishing and languishing of living things gives us no antecedent reason to expect the majority of living things will thrive. Thus, on B & D & N, E1 is just what we would expect.

In contrast, B & D & T entail both that God does not need to create a world in which only a fraction of living things, including sentient beings, thrive, and that, if such a world exists, then God had good moral reasons for allowing this state of affairs to obtain. If T is true, why would God create a world in which all sentient beings savagely compete with one another for survival? Thus, T mystifies E1.

Comments on (4)

Note that while the above argument implies that we have a good prima facie reason to believe that T is probably false (since T and N are incompatible), it does not imply that we have a good prima facie reason to believe that N is true (since T and N are not jointly exhaustive and so could both be improbable). So the argument from the flourishing and languishing of sentient beings could be more accurately described as an argument against T than as an argument for N, though of course in some sense it is both.