Religious counterparts will often point out that many scientists are religious, and that most, if not all, scientists in the past were religious as well. This claim is often propped up by such big names as Kepler, Galileo and Newton, and is commonly capped off with a challenge to nonbelievers that takes the form of “Who are you to claim to be smarter than those great religious scientists?”.

There are a number of effective ways to debunk this argument:

1. Start by pointing out that that just because two things exist alongside each other, it doesn’t mean they are compatible. A good example of this is infidelity existing alongside, or even inside, marriage. If you’re looking for a harsher example, why not point out that child rape and torture has existed alongside, or inside, the Catholic church for centuries. Does this mean that marriage and infidelity are compatible, or that child rape and torture is compatible with the Catholic church? Religious compatibility is a tricky game to play when you consider the histories of most religions, and how many more ways there are for religions to lose rather than gain credibility in such a game.

2. Point out that religion is just as compatible with science as astrology is with astronomy, and alchemy is with chemistry – and for the same reasons. There was indeed a time when astrology and astronomy were blended together, alchemy was a subject within the wider field of chemistry, and yes, science was strongly connected to religion. But these fields started to split apart as soon as the modern scientific method began to take hold a few centuries ago. Just like Mars exploration missions do not require astrological maps, and are unaffected by the Roman god of war objecting to yet another incursion of a new rover onto his realm, so we do not need to consult any Iron Aged scriptures or wonder what Yahweh or Allah might think about such things as Stem Cell research.

3. Lastly, religious apologists like to point out that many of the great scientists would not have been inspired to greatness, and would not have achieved so much, had it not been for their religious faith. Though this objection is not a particularly strong one, it is worth noting that the connection it attempts to establish between religion and science is a causal rather than an incidental one. In effect, it attempt to establish the truth of religion by insinuating that it is responsible for inspiring scientific advancements; an insinuation that you can easily make your counterpart regret having made.

Start by pointing out that the baseline fundamentals of western science were laid out by polytheist Greeks, centuries before the birth of Christ. Does this mean that Greek Mythology must also be true, or that the Christianity of the great scientists is based on Greek mythology? Point out the huge contributions to astronomy, chemistry and medicine that came from Muslim scientists, during what is known as the Islamic Golden Age. Wouldn’t this make Islam true as well? This Golden Age, by the way, coincided with the European Dark Ages – a period of considerable Christian religiosity and scientific backwardness. Would this mean that during the Dark Ages Christianity was not as true as Islam? On top of that, the scientific advancements of the vastly superior Indian and Chinese empires far exceeded those of the Christian world for quite a few centuries. Does this mean that Hinduism, Taoism, Confucianism and Buddhism are all true as well, or were true in the past?

It’s generally a good idea for religious apologists to steer clear of even hinting at causal connections between religion and science, unless they want to establish that degrees of religious truth can be determined by calculating degrees of scientific progress, in which case we can all but establish that god no longer exists, based on how irreligious so much of the scientific community is these days.