From the mail:
Just read your On Religious Pluralism and Religious Tolerance entry, and I have one concern. Is it really right to view the New Atheists, and atheists in general, as "not religious"? I imagine this really depends on how you yourself define religion, and I admit to not knowing that. [. . .]
I don't know it either [grin].
The question as to what religion is is not at all easy to answer. It is not even clear that the question makes sense. For when you ask What is religion? you presuppose that it has an essence which can be captured in a definition that specifies necessary and sufficient conditions. But it might be that the concept religion is a family resemblance concept like the concept game (to invoke Wittgenstein's famous example). Think of all the different sorts of games there are. Is there any property or set of properties that all games have and that only games have? Presumably not. The concept game is a family resemblance concept to which no essence corresponds. Noted philosophers of religion such as John Hick maintain the same with respect to the concept religion.
If you take this tack, then you can plausibly argue that Marxism and secular humanism and militant atheism are religions.
But it strikes me as decidedly odd to characterize a militant anti-religionist as having a religion. Indeed, it smacks of a cheap debating trick: "How can you criticize religion when you yourself have a religion?" I prefer to think along the following lines. Start with belief-system as your genus and then distinguish two species: belief-systems that are theoretical, though they may have practical applications, and belief-systems that are by their very nature oriented toward action. Call the latter ideologies. Then distinguish between religious and non-religious ideologies. Marxism and militant atheism are non-religious ideologies while the Abrahamic religions and some of the Eastern religions are religious ideologies.
But this leaves me with the problem of specifying what it is that distinguishes religious from non-religious ideologies. Perhaps this: all and only religions make reference to a transcendent reality, whether of a personal or impersonal nature, contact or community or identification with which is the summum bonum and the ultimate purpose of human existence. For the Abrahamic faiths, Yahweh, God, Allah is the transcendent reality. For Taoism, the Tao. For Hinduism, Brahman. For Buddhism, the transcendent state of nirvana. But I expect the Theravadins to object that nibbana is nothing positive and transcendent, only the extinguishing or dissolution of the (ultimately illusory) self. I could of course simply deny that Theravada Buddhism is a religion, strictly speaking. I could lump it together with Stoicism as a sort of psychotherapy, a set of techniques for achieiving equanimity.
There are a number of tricky and unresolved issues here, but I see little point in calling militant atheism a religion, though I concede it is like a religion in some ways.