Interestingly, it seems that all of the main strands of Judaism -- Orthodox, Conservative, and Reform -- emerged in the 18th and 19th centuries, and each can be seen as a reaction to modernity (somewhat similar to how Christian fundamentalism is a thoroughly modern ideology).
Reconstructionist Judaism is more of a 20th century North American phenomenon. I haven't yet gotten up to that chapter, but my limited understanding is that it is like a Jewish version of Unitarianism, i.e., they believe in no more than one God.
I found the discussion of the differences between Orthodoxy and Hasidism to be especially interesting. I trust that Gandalin will let us know if this is a simplistic caricature, but you could say that the Orthodox are analogous to scholastic philosophers poring over scripture and creatively engaging God's living law. Hasidism emerged as a kind of reaction to this, and is throughly mystical, experiential, ecstatic, and individualistic (i.e., not so much focused on the community).
The reason I find this interesting is that one finds this same complementarity in eastern and western forms of Christianity, i.e., Catholicism and Orthodoxy. And indeed, Hasidism emerged in eastern Europe whereas Orthodox Judaism reflects its highly intellectual and more "civilized" German culture.
Many German Jews apparently looked down on their eastern brethren as more than a little uncouth, uneducated, and superstitious; ironically -- considering what happened later -- many of them would have related more to their fellow non-Jewish Germans than to Polish or Russian Jews.
Anyway, the parallel to eastern and western forms of Christianity is intriguing. Eastern Christianity, unlike Catholicism, has never, to my knowledge, developed any systematic theology a la Thomas Aquinas. You might say they missed that boat entirely, and never made any attempt to reconcile revelation with modernity or science or rational philosophy.
Rather, like the Hasidim, they focus on the mystical and experiential. In fact, I would simply define mysticism as the experiential -- as opposed to intellectual or behavioral or (merely) emotional -- aspect of religion. It can never really be absent -- for example, the most intellectualized truth nevertheless must be experienced.
It's somewhat analogous to the distinction between light and heat. Intellectual light generates its own warmth, just as mystical heat radiates its own light. Or, just say mind and heart. Every human is equipped with each. At the start.
Imagine a giant global brain with western/left and eastern/right brain cerebral hemispheres.
Wait -- before you go any further -- can I buy some pot from you?
Anyway, come for the light, stay for the warmth. Or vice versa. A full service religion will feature both.
Back to The Tao of Christ. Speaking of experience, the author cautions us that mere knowledge (k) of revelation is useless; for it "cannot be separated from life," but rather, calls "for a radical transformation of our whole being."
In order to cover all the bases, we need to superimpose a cross over the brain. Thus, in addition to the left and right hemispheres, there is literally a higher and lower brain(s) -- there is the neocortex, under and behind which are the mammalian and reptilian brains, so to speak. And at the top of the spine there is the primitive brainstem of the simple Democrat. It assures respiration, a beating heart, and the ability to apply for food stamps, but little else.
Now, where is the source of our problems? Yes, life is problems. If you are dead, you have no problems. But where in the brain are our problems coming from? Well, I suppose it depends.
They say -- they being developmental neurologists steeped in attachment theory -- that they are stored away in the preverbal right cerebral hemisphere, which is why they are so difficult to detect and eradicate. They are beneath the reach of language, so to... not speak.
But there is a more general, universal, unavoidable problem associated with the human condition, and it is this upper and lower storey business. Freud supposedly thought he had discovered something new with his distinction between the primitive id and the civilized ego, but really, how could one fail to notice?
I remember, for example, when I was a bachelor living in Hermosa Beach. I would torture myself by riding my bike on the path along the beach. Suffice it to say, I did not have to think about scantily clad bodies in the sand. Rather, the thoughts bombarded me, entirely outside my will.
Phone rings. Unexpectedly called into work. On this perfect day for staying indoors, the first rainy day in over a year. Oh well. Life is problems.