The question of secularism tends to be confused by secularists themselves. There is a book on the subject: http://www.amazon.com/How-Not-Be-Secular-Reading/dp/0802867618
The new atheists, and the secular humanists before them have driven the term secular into a cul de sac: it refers to a perspective that must be atheist, accept darwinism, scientism, and lately we have found figures like Sam Harris try to exclude buddhist enlightenment from ‘secularism’.
This is a hopeless mess that will backfire. In the original sense of the term, Protestants, for example, were secular before anyone else, and it is impossible to claim that atheism is the exclusive outcome of philosophic belief as modernity. The secular, in fact, refers to a periodization scheme and has no intrinsic religious or anti-religious content. One of the confusions centers around Spinoza: there is near cult unspoken of Spinoza’s construct with its ‘atheism, causal monism’, etc, and this is taken as the defining standard of modernity. Thus figures in exception, like Kant, etc…, are thrown out. This Spinoza cult is stronger than we think because it is almost a stealth operation. We see it in historians like Jonathan Israel.
But this narrow a view won’t work, although variants of it threaten to take over the definition of modernity. It is an unfortunate development.
The solution is to take secularism as a form of secular periodization, that corresponds to the rise of a new era in the sixteenth century. That was how the word originated in the sudden sense of the way the Reformation and other factors seemed like the dawn of new epoch. In that context we can take dialectical complements as constituting the secular, these given in the clear progression of the modern transition from the sixteenth to the nineteenth century: the Reformation and the Scientific Revolution are one classic contrast, both secular. The whole history up to the Enlightendment and the French Revolution more or less show the way the ‘secular era’ is staged as a vast universe of discourse. Definitional philosophic secularism is crippled by its obsession with a narrow set of modern themes: Spinoza, the new physics, the philosophes, if they were atheist, but excluding most of the rise of modern philosophy, the Romantics, and everything not in the mold of the positivistic sciences. This trend is first seen early on but becomes very explicit with the reaction to the Hegel school in the era of Marx, Feuerbach, soon the Darwinists, and hard materialists of the era. Trying to cherry pick modernity for a definition of secularism is completely counterproductive. People are brainwashed to think a criticism of darwinism is anti-secular, ridiculous. The magnificent school of the teleomechanists, derived from Kant, resolved the issues now plaguing biology, but are now totally suppressed. Books that even mention them, like my Descent of Man Revisited are simply blacklisted. Noone ever discusses them now. It is a crazy situation, but it can be understood by looking at my ‘macro model’ in WHEE: an explicit ‘modern transition’ with all these complementary ’emergent innovations’ comprising its content and effect, and closing way before our present at an explicit but rough ‘divide’ point around 1800 and a little later. This model can explain why those who are the immediate successors to the transition might downshift into an almost parodist version of modernity that excludes almost everything except a narrow scientism. People begin to forget what modernity really means.
The issue is compounded now with the flood of new age movements taking the narrow secularists at their word and plotting the downfall of modernity. But that is not the point and very destructive. It is possible to claim that new age confusions are not modern in character, but in the final analysis they are really the progeny of the original Reformation. Hardly a single new age cult that doesn’t try to reckon with modernity manages to survive long, a sign a new aspect of the ‘reformation’ is at work. The issue of buddhism is especially confusing, but buddhism actually represents an earlier birth of the ‘secular’ as it tried to overtake and replace Hinduism, in vain. But the character of the buddhist revolution seems almost like the Reformation appeared early in the world of India. A similar sentiment can arise from studying the Greek phenomenon of antiquity: all the categories of the secular are first born here in embryonic form. Buddhist documents at the early starting era almost sound like scientific autopsies (of the ego, we should guess) in their probing toward making a ‘science’ of the Hindu profusion of religious forms. The steps toward an understanding of the human psychological condition is done systematically without any fancy side meats we find in Hindu spiritual legacies. This is reason buddhism sneaked into modernity like an invasion of church mice in the era of Herder and Schopenhauer who noted it directly and recast the whole buddhist psychology of such in his manner of a beautiful variant of Kantian transcendental idealism. This stealth entry of buddhism, as something that almost had to be included in modernity, but wasn’t indigenous to Europe, was another of the mysteries of the modern transition. At some point a more complex reformation of buddhism will emerge as its form of the future.
The need to do define a larger and more culturally intelligent version of the secular that can speak to issues of religion, philosophy, art and the rest of the factors banished from the minds of secular humanist obsessives. Many of these people have a nervous breakdown confronting liberal arts education in colleges. This is almost beyond belief, but points to one of the reasons for the confusion: a large phalanx confronting modern educational systems batten down the hatches around science tracks and try to evade absolutely anything else. The result is a new kind of ‘smart idiot’ easily converted to the narrow pseudo-philosophic ‘secularism’ of this new cult of ‘secularism’ newly branded.
And here the modern left via marxism needs to adopt a larger perspective of modernity also, and not pretend that the era of the Hegelian twilight had all the answers in terms of now dated materialism, ideological darwinism, and Iron Cage scientism.