Jerry Coyne asks what this means, and proposes two meanings “accepting that the ideas may be credible” and “realizing that these ideas have a real impact on society.” Coyne thinks religious ideas should be taken seriouly in the second sense but not the first.
I’m tempted to cheer Coyne on, but (1) there’s another important interpretation and (2) the first interpretation is ambiguous. The third interpretation would be “accepting that it’s important to undrstand whether and why the idea is right or wrong.” Religion fits this sense of deserving to be taken seriously, as do other ideas that I find detestable, such as Plato’s totalitarianism.
The other problem is that “may” is ambiguous. If its “may as far as we know,” it’s important to know who the “we” is. Plato’s totalitarianism shouldn’t be thought credible to anyone who knows human history and psychology, but I can understand how it could seem credible to somone without that knowledge. I think the situation with religion is similar.
I’m tempted at first to think that ‘it’s important to understand whether and why an idea is right or wrong’ if the idea either ‘may be credible’ or ‘has a real impact on society’.
OTOH it may be important to understand an idea even if it is incredible or without social impact because it may help us understand *other* ideas which are either credible or socially significant.
I agree that Plato’s totalitarian leanings are troublesome. But some do seem to be persuaded of it, and certainly many have acted as though we should practice the methods advised by his ‘Republic’.