In an earlier post, I discussed what I thought was a useful distinction between ‘thin theism’ and ‘thick theism’ that was provided by Paul Russell in his article published in the Stanford Encyclopedia of Philosophy that discussed David Hume’s complicated views on religion.

Russell describes thin theism as consisting of the belief that “there exists some (invisible) “supreme intelligence” that is the origin, creator and governor of this world” and that there is “no commitment to some further, more specific, set of attributes.” By contrast, thick theism ” presupposes a richer set of attributes, such as infinity, omniscience, omnipotence, and moral perfection.”

In the comments to that post, Reginald Selkirk suggested that if thin theism becomes too thin, then it begins to more resemble deism. But is there a smooth and continuous transition from thin theism to deism so that we cannot draw a sharp line between the two or is there a discrete gap, however small, that makes it possible to always maintain a distinction between deism and theism, however thin?

These passages by J. C. A. Gaskin from his introduction to the 1993 Oxford World Classics publication of Hume’s Natural History of Religion (1757) and Dialogues Concerning Natural Religion (1779) by Oxford World Classics suggests that it is possible.

Theism is the belief that (a) one and only one all-powerful God exists, (b) that this single God created the universe and is the ultimate reason for or explanation of all that is, and also (c) that God remains active and everywhere present (“immanent”) in his creation, sustaining it in being, answering prayers, causing miracles on special occasions, and revealing himself and his purposes to mankind both in special revelations (e.g. through Abraham or Jesus or Mahomet) and in the general human experience of the divine. (p. x)
…

Deism is a philosophical view of religious belief which accepts (a) and (b) on (and only on) the basis of the arguments and evidence produced in their favor, but rejects (c) in general and the notion of special revelation in particular. It thus technically avoids atheism while rejecting the Christian or any other particular revelation of an immanent God. The Deity is indeed the Great Architect of the universe, but is not busy in a minute part of it answering prayers, performing miracles, dictating laws for the patriarch of an ancient tribe, or advising the leader of a modern cult. (p. xii)

It is the presence of the word ‘governor’ in the definition of thin theism that is crucial because it implies some controlling behavior on the part of the deity. Belief in any activity by the deity, however minor, immediately shifts a deist into the theist camp. Of course, anything that depends on how words are defined is always arbitrary but these definitions seem to me to be quite reasonable and help to clarify the distinctions and thus avoid people talking at cross-purposes.

Although we think that deism is a more robust belief than theism, Gaskin says that that is not the case, since the deist’s belief depends more strongly upon evidence than that of the theist.

If the evidence for (a) and (b) is defective, the theist still has something to cling on to in (c), even if it is only some version of ‘blind faith’ in the revelation, augmented by ‘personal religious experience’; and since acceptance of (c) presupposed the truth of (a) and (b), theism as belief may survive the destruction of its rational basis. The deist, on the other hand, having already rejected (c) on whatever grounds, has nothing left but atheism if the arguments for accepting (a) and (b) are null and void. (p. xiii)

Genuine deists would dissociate themselves from any specific religious tradition. But I have noticed that the sophisticated religious apologists that debate issues of religion in the public sphere and use deistic arguments in those contexts are almost always also believers of a specific religious tradition, and so are theists and not deists.

As science has progressed, the evidentiary support that deists depended upon, that largely depended upon what seemed to them to be the inexplicability of nature without an intelligent deity to create it, has been undermined. The world and the universe is no longer a deep mystery. This may explain why there are so few genuine deists left. They have had to choose between becoming atheists or theists.