Appeals to Common Practice Don’t Make Science and Religion Compatible

June 17, 2010

Science and religion are compatible because some scientists are religious, according to Alan Leshner , CEO of the American Association for the Advancement of Science (AAS) and executive publisher of Science . To be sure, anyone with an ear to the debate over science and religion has heard this argument before. But when critically analyzed, it is wholly unconvincing. 

The practical evidence wielded for the compatibility argument usually includes people like Francis Collins, the geneticist and Director of the National Institutes of Health who is an evangelical Christian . If devout religious believers can be scientists, the argument goes, there is no tension between the scientific and religious approaches to the world. Yet this line of thought ignores the real issue: the difference between practice and theory (or, is and ought ). In practice, clearly scientists can be religious and hold religious beliefs (though they are overwhelming less religious and more secular than the general American public). But in theory, the scientific and religious outlooks are philosophically incompatible (for more, see here and here . To be clear, I don't think science demands atheism purely due to epistemological matters, but I don't think science and religion are compatible, either. More on this in a forthcoming essay).

Indeed, consider the logic of Leshner's argument:

1. Many scientists are religious/have religious faith.

2. Therefore, science and religion/religious faith are compatible.

And now imagine instead that the following argument was being made:

1. Many people drink alcohol and drive.

2. Therefore, drinking alcohol and driving are compatible.

We would obviously object here, and we would be absolutely correct to do so. Yet the drunk driving logic is no different than the logic Leshner uses to boast of the compability of science and religion. This is precisely why philosphers file Leshner's argument under the "appeal to common practice" fallacy : even if a majority of people believe in something or engage in some practice, that does not mean the belief or practice is acceptable, correct, justified, or reasonable. If one wants to make a case for the compatibility of science and religion, he or she must not point to the abundance of easily partitioned human brains, but instead provide philosophical reasons why science and religion are actually congruous and do not conflict. 

For further reading, Leshner's essay is being discussed on the blogs of Jerry Coyne , Ophelia Benson, and Russell Blackford


#1 Ophelia Benson on Saturday June 19, 2010 at 5:43pm

Or one could also say

1. Many people text and drive.

2. Therefore, texting and driving are compatible.

Which is true in a sense, but it ain’t good practice!

If only driving were peer reviewed!

But seriously folks. In a sense most of the people who like to claim that science and religion are compatible know very well they’re not, except in the superficial sense you’re pointing to here, because they don’t combine the two *when they’re doing science*. They don’t combine the two at the bench. They combine the two verbally, when chatting to the public or at AAAS conferences on science & religion 0 but not when they’re actually doing scientific research. This fact is surely telling.

#2 Josh Slocum (Guest) on Saturday June 19, 2010 at 6:34pm

Very nicely written, Michael. This is what so many of us have been saying - and I think very reasonably - all along. It’s been frustrating to be met with “answers” to this position that avoid the epistemological problem, and just appeal to the “well, certain people are both religious and scientific” claim.

Thanks for getting it, taking it seriously, and articulating it so clearly.

#3 steve (Guest) on Sunday June 20, 2010 at 8:04am

Well, I don’t know about that.

Lots of pedophile catholic priests around and the rcc seems to be very comfortable with institutionalized child abuse.

#4 Rodney Coooper (Guest) on Sunday June 20, 2010 at 5:47pm

I think you’ve made this much more complicated than it needs to be.  A simple “Appeal To Authority” would suffice:  “I’m a scientist.  I believe there is a God.  Therefore, there is a God.”  I’ve never heard of “Appeal to Common Practice”  If it’s valid, I still think it’s off target, because most scientists aren’t religious, taking the “Common” out of “Common Practice”.  I’ve looked at the “List of Fallacies” on Wikipedia and couldn’t really find a fallacy to fit the way you’ve framed the argument.  Perhaps someone else could find a fit.  Take a look.



#5 Josh Slocum (Guest) on Sunday June 20, 2010 at 6:27pm

Actually Rodney, I think Michael’s “Appeal to Common Practice” is a more accurate description of the phenomenon he’s criticizing. Sure, it’s probably a subset of the Argument From Authority, but what makes it “special” is that the compatibilists are appealing to how putatively common it is (and it isn’t, really, when you look at the numbers) for scientists to also be religious.

Maybe that’s a subtle distinction, but I think it’s a useful one.

#6 Rodney Cooper (Guest) on Sunday June 20, 2010 at 9:53pm

You know Josh, I can’t swallow that reasoning whole.  To say “Many scientists are religious/have religious faith.”, is a very complex sentence to dissect.  I’m not even sure if it’s grammatically correct.  And the fallacy is one I’ve never come across.  It seems contrived from other accepted fallacies; not that it isn’t logical; that doesn’t seem to be the problem.  Thoreau said, “Simplify, simplify, simplify.”  I think there’s a better way to communicate what De Dora is trying to convey.  Care to take a stab at it?

#7 Ophelia Benson on Monday June 21, 2010 at 4:13am

I don’t think Thoreau meant simplify arguments!

And if he did, so what; argmt from authority.

#8 Rodney Cooper (Guest) on Monday June 21, 2010 at 3:40pm

Yes!  Appeal to authority is surely in there.  The example is so complex that I think you could find a few possible fallacies in it, depending how you break it down, which is subjective.  I think the sentence “Many scientists are religious/have religious faith.” is very complex.  I don’t even think it’s grammatically correct.  If your going to make a claim, which is the first step in criticism, you must be clear on what that claim is.  I think De Dora is being much too general in his initial claim.  He could have simply said, “I’m a scientist.  I believe in god. Therefore, god exists.”  We can easily subject that claim to critism.  I suppose he could have gotten fancy and said, “Four percent of members of the National Science Foundation are Presbyterian.  Therefore, Presbyterianism is true.  That’s an easy claim to subject to criticism.  Anybody with me on this?

But this is really about what Leshner said, which in my opinion is an obtuse, even non-sensical, statement.  He’s making words mean, what they clearly don’t mean.  “Science and religion are compatible, because some scientists are religious.”; specifically, “science”, “scientist”, “religion”, and “religious”; all very complex concepts.  De Dora has his work cut out for him, trying to find a concise claim in that statement.  Taking short cuts serves no one in this endeavor.

#9 Daniel Mann (Guest) on Sunday July 11, 2010 at 12:13pm


I’m afraid your analogy comparing drunk driving with Christians doing science doesn’t work. Leshner is not simply pointing out that Christians do science and therefore they are compatible. He seems to be suggesting that Christians do GOOD science, whereas drunkenness doesn’t improve driving. It impedes good driving.

You therefore must demonstrate that there is something endemic to the Christian belief system that interferes with doing good science, good philosophy…

#10 Havok (Guest) on Monday July 12, 2010 at 7:58pm

Daniel, perhaps you should follow the links in the article which point out in what ways religious belief and the scientific endeavour are incompatible before stating that this must be demonstrated?

“But in theory, the scientific and religious outlooks are philosophically incompatible   (for more, see here and here.”

#11 Michael De Dora on Tuesday July 13, 2010 at 9:33pm

Someone has responded to my post. I am currently digesting.

#12 Michael De Dora on Tuesday July 13, 2010 at 9:39pm

@Daniel Mann,

“You therefore must demonstrate that there is something endemic to the Christian belief system that interferes with doing good science, good philosophy…”

Christians can do good science, that seems obvious. Good philosophy, perhaps that too. But as you might suppose, I consider religious views to be philosophical views. And I do not tend to like religious views.

#13 Daniel Mann (Guest) on Wednesday July 14, 2010 at 3:47am


Although you are correct that religious views are philosophical views, they also entail propositions – historical, psychological and otherwise—that are amenable to verification.

You also wrote, “I do not tend to like religious views.” Would you care to elaborate? (Don’t we all have religious beliefs like naturalism?)

#14 Michael De Dora on Wednesday July 14, 2010 at 7:44am

@Daniel Mann, I’m not sure I have the patience for that sort of conversation. Suffice to say I believe Christianity is a religion, and I find its foundational tenets generally false, while I believe naturalism is a philosophy, one that is that is supported well-supported by reason.

#15 Daniel Mann (Guest) on Wednesday July 14, 2010 at 9:35am


You claim that naturalism is well-supported by reason. While we both acknowledge that things happen according to formula in predictable ways, governed by laws, what reasons or evidences do you have that these laws are natural and un-intelligent?

Instead, I think it makes far more sense that they emanate from the mind of God. Without this, you are left with a number of independent natural laws/forces, all self-sustaining and self-originating.

#16 dimitar zdravkov (Guest) on Saturday July 17, 2010 at 4:10am

SCIENCE & RELIGION CONNECT-BIBLE CODE UNLOCKED!-According to the Bible the world has been created in six days,but according to the Science this process has taken billions of years.If we exclude the difference in time and we pay attention to the SEQUENCE,we will see that there is no contradiction between both,but only the question-why in the Bible things happened so fast?There is an answer and it`s in the Bible itself.Moses described the Creation from his own sight as an eyewitness.Where and when he saw It,how could he have seen something happen before his existence?Answer:For forty days he has been at the mount Sinai where he got information about the past,present and future.The Creation had been REcreated to him in six days there,he had seen how the already existing world had been made.The long process of evolution had been shown to him in the first six days and the SEVENTH day had been dedicated to human`s appearing.After that he had seen the difference between Adam`s origin and Eve`s one.Adam comes from the dirt in the process of evolution,but Eve comes from DNA material out his body,which marks another jump for the evolution or in other words-the"missing link” which Science is looking for.The Creation continue and The Next Jump Is Coming…2012 ?!

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