"There are reverent minds who ceaselessly scan the fields of Nature and the books of Science in search of gaps," wrote Henry Drummond, "gaps which they will fill up with God. As if God lived in gaps?"
In his Lowell Lectures on the Ascent of Man , Drummond continues:
When things are known, that is to say, we conceive them as natural, on Man's level; when they are unknown, we call them divine—as if our ignorance of a thing were the stamp of its divinity. If God is only to be left to the gaps in our knowledge, where shall we be when these gaps are filled up? And if they are never to be filled up, is God only to be found in the dis-orders of the world? Those who yield to the temptation to reserve a point here and there for special divine interposition are apt to forget that this virtually excludes God from the rest of the process. If God appears periodically, He disappears periodically. If He comes upon the scene at special crises, He is absent from the scene in the intervals. Whether is all-God or occasional-God the nobler theory?
Drummond, a 19th century evangelical writer and lecturer, originated the term "God of the gaps" while chastising his fellow Christians for their unscriptural view of natural history. Unfortunately, this confusion about "natural" and "supernatural" continues today even though it is, as philosopher Alvin Plantinga explains "at best a kind of anemic and watered-down semideism" that "is worlds apart from serious Christian theism."
For Christians, though, a "natural" process is just a normal-appearing process which remains the providential design and control of God. The difference between natural-appearing and miraculous-appearing processes is not whether God is acting — his action occurs in both processes — but the way in which he chooses to act.
So what then does "God of the gaps" mean? The phrase, according to chemist Craig Rusbult, actually encompasses four different views based on distinctions between a "science gap" (a gap in our current scientific knowledge) and a "nature gap" (a break in the continuous cause-effect chain of natural process) that may or may not be bridged by miraculous-appearing theistic action. The four views are:
An "always in the gaps" view — the claim that we should always assume that a science gap is a nature gap
An "only in the gaps" view — which implies that God works only in nature gaps, that God is not active in natural process and defines "natural" in a way that means "without God."
A "gaps are possible" view — a humble claim that "maybe God exists, and maybe nature gaps exist"
A "gaps are impossible" view — a belief that: 1) God does not exist, so nature-gaps are physically impossible, or 2) God does exist, but a nature-gap is theologically impossible because God would never allow it.
Rusbult recommends discarding the confusing phrase. But, he suggests, when someone criticizes a theory by calling it a "God of the gaps" theory ask "What exactly do you mean by this?"
Does it refer to a "gaps are possible" view (this is theologically acceptable for a Christian theist) or a specific theory claiming "a gap did occur" (this should be evaluated using evidence and logic), or an "always in the gaps" habit (that is scientifically naive) or an "only in the gaps" view (that is theologically unacceptable and should be criticized)?
An "always in the gaps" view is scientifically naive while an "only in the gaps" view is theological unsound. Claiming that God does not exist, so nature-gaps are physically impossible, is also an unsophisticated and unsupportable claim. Saying that God does exist, but a nature-gap is theologically impossible because God would never allow it, is simply pretentious.
The most reasonable position is the view that "gaps are possible," a broad spectrum that ranges from "gaps are exceedingly likely" to "gaps are statistically improbable." Because this breadth allows for a significant amount of wiggle room, the view that gaps are possible isn't very useless as a descriptive category. In fact, there is a large variance even among those who believe God (or, at least, some intelligent being) is the cause of all creation.
Some people, for example, believe that simply finding evidence of intelligent agency is sufficient to explain "gaps" while others (including me) believe that such data is simply the starting point for postulating a more robust explanatory framework. After all, the whole of creation — including all processes, all "natural" laws — are the actions of an intelligent agent, the divine Creator and Sustainer of the universe. The distinction between natural-appearing and miraculous-appearing is, again, a matter of which way God chooses to act. "Natural" laws that require low-information content are as much a product of purposeful design and intentionality as the most complex processes.
There is also no reason to be concerned that scientific discoveries will relegate God to a secondary role. Closing "science gaps" almost always has the opposite effect. Science is an hydra-headed creature; with every "science gap" that is closed, two more rise up to replace the one that is bridged. For example, when evolution was first proposed by Darwin, there was no explanation for the mechanism of transmission of traits from one generation to the next. With the discovery of DNA, Watson and Crick appeared to close that particular "gap" and replaced it with a gene-centric theory. But that theory created new gaps that need to be closed:
The gene-centric view is thus 'an artefact of history', says Michael Eisen, an evolutionary biologist who researches fruit flies at the University of California, Berkeley. 'It rose simply because it was easier to identify individual genes as something that shaped evolution. But that's about opportunity and convenience rather than accuracy. People confuse the fact that we can more easily study it with the idea that it's more important.'
The gene's power to create traits, says Eisen, is just one of many evolutionary mechanisms. 'Evolution is not even that simple. Anyone who's worked on systems sees that natural selection takes advantage of the most bizarre aspects of biology. When something has so many parts, evolution will act on all of them.
'It's not that genes don't sometimes drive evolutionary change. It's that this mutational model — a gene changes, therefore the organism changes — is just one way to get the job done. Other ways may actually do more.'
The biggest science gap in biology remains the origin of life. As physicist David Snoke notes, no one today has an adequate explanation for how this highly complicated molecule arose out of nowhere. Also, we do not have an adequate explanation within chemical evolutionary theory for the appearance of the mechanism that gives us a readout of the information, or for the appearance of methods that replicate information with out error, or for the appearance of the delicate balance of repair and maintenance of the molecular systems that use the information stored in DNA.
God does not appear periodically in nature only to disappear again. He does not come upon the scene at special crises to fill in the "gaps" in our knowledge, nor is he absent from the scene in the intervals. The God of Christianity is not a mere "god of the gaps" but is the ever present, always working, Creator, Sustainer, and Redeemer of all creation. The only real gaps that need to be filled are the knowledge gaps that exist between our ears.