Is Secular Buddhism an oxymoron?
In a way, calling oneself a secular Buddhist is an oxymoron when we consider secular Buddhism under the contradictory terms loka-dharma,which is Pali for worldly matters and lokuttara,which applies to the supermundane such as the Noble Path or, in Sanskrit, arya-marga. I should mention that the Buddha of the Mahayana canon is always considered to be lokottara which is Sanskrit for supermundane. By the way, my source for all this comes from the book, A Dictionary of Buddhism by Damien Keown (not a bad book to have in your libraries dear Zennistscheck it out on Google Books).
But of course there is nothing immoral about being a secular Buddhist although it is arguably inconsistent with the higher practices of Buddhism which lead to nirvana. However, the question arises, how can one pursue the supermundane path of the Buddhas by means of a mundane vehicle? Sound impossible? Well it is!
Lets be honest, secular Buddhism is prithagjana Buddhism, prithagjana referring to an ordinary person or the same, a worldling who has not attained the path of seeing (darsana-marga) which is insight into transcendent truth. (I suppose a hardcore secular Buddhist couldnt care less about seeing the transcendentits horsefeathers.)
In my humble opinion, what allows the secular Buddhist not to receive a well deserved snicker is that most Western Buddhists have a strong belief in science which they believe has sufficiently demonstrated there is nothing transcendent like some ultimate mind stuff. When we diethats itwe don't re-become/punarbhava being again trapped in Mind's phenomenalizations. In other words, death is nirvana.