Informal Statement of the Argument
If there is a single theme unifying the history of science, it is that naturalistic explanations work. The history of science contains numerous examples of naturalistic explanations replacing supernatural ones and no examples of supernatural explanations replacing naturalistic ones. Indeed, naturalistic explanations have been so successful that even most scientific theists concede that supernatural explanations are, in general, implausible, even on the assumption that theism is true. Such explanatory success is antecedently more likely on naturalism–which entails that all supernaturalistic explanations are false–than it is on theism. Thus the history of science is some evidence for naturalism and against theism.
physical entity: the kind of entity studied by physicists or chemists. Examples of physical entities include atoms, molecules, gravitational fields, electromagnetic fields, etc.
causally reducible: X is causally reducible to Y just in case X’s causal powers are entirely explainable in terms of the causal powers of Y.
ontologically reducible: X is ontologically reducible to Y just in case X is nothing but a collection of Ys organized in a certain way.
natural entity: an entity which is either a physical entity or an entity that is ontologically or causally reducible to a physical entity.
nature: the spatio-temporal universe of natural entities.
Note: there may be additional entities currently unknown to physics but which may be discovered in the future. If and when such entities are discovered, they may be called physical and natural based on their relationship to known physical or natural entities. Thus, this definition of “nature” may only capture nature as currently understood.
supernatural person: a person that is not part of nature but can affect nature. Examples of supernatural persons include God, angels, Satan, demons, ghosts, etc.
non-natural entity: any entity that is not a natural entity. There are two kinds of non-natural entities: personal and impersonal. Personal non-natural entities are supernatural persons or agents. Impersonal non-natural entities are abstract objects.
presumption of naturalism: prior to investigation, the probability that the immediate cause of any given natural event is very high.
modest methodological naturalism: scientific explanations may appeal to the supernatural only as a last resort.
naturalistic explanation: a non-supernatural explanation.
Note: a common misunderstanding is the idea that a “naturalistic explanation” means an explanation based on metaphysical naturalism. That is not how “naturalistic explanation” is used here. Rather, a naturalistic explanation simply means any explanation that does not appeal to supernatural agency.
B: The Relevant Background Information
E: The Evidence to be Explained
Rival Explanatory Hypotheses
The Argument Formulated