Materialism, Spiritualism, and Humanism

(inspired by reading Douglas Hofstadter)
Why should spiritualism and materialism be incompatible? Or spiritualism and humanism?
Consider: materialistically, the human brain is a lump of matter not much bigger than two fists, the thoughts that one perceives nothing than chemical reactions and the firing of neurons. Yet this utterly insignificant lump of chemistry is capable of modeling an entire house, many times bigger than itself. It is capable of perceiving the expansiveness of a mountain range. It is capable of enveloping within it's processes the workings of the universe. And, if this brain is the brain of a fiction writer, of creating and managing universes of its own, such as the worlds of Harry Potter and Lord of the Rings, which contain within them characters with thought processes seemingly of their own. Is there not something profoundly spiritual in that?
There is room for souls in a materialistic universe, as long as one is willing to expand their notion of a soul, not as some immaterial ghost that inhabits our minds, but as a natural creation of the processes of our brains. This makes it no less real! To say the soul doesn't exist because it's "no more" than chemical reactions...well, one might as well argue that happiness, sadness, love, war, the law do not exist either. These are all ideas, and ideas are "nothing more" than chemical processes, yet they exert an obvious influence on the world, they interact with each other, and they operate in ways of their own (look up emergence theory). Or one could argue that this computer, my chair, cars, blocks of wood, and any other of the many things which to us humans have obvious existence are nothing more than the interaction of subatomic particles. In fact, at a certain level, it IS meaningless to talk about the distinction between objects, because at a small enough level there really isn't any such distinction: you cannot say "that atom belongs to the computer and that atom next to it belongs to the desk". So if one is going to argue that the soul does not exist because it's "nothing more" than a collection of chemical processes one must also be willing to argue that computers, chairs, cars, and block of wood don't exist either. It all becomes very Zen-like, which isn't a problem, but involves operating at an entirely different level. Indeed, it's all a question of levels: you get to the subatomic level and the distinction between objects and the concept of a soul have dissappeared, you get to a galactic level and object and souls are so insignicant that distinctions between them disappear, but somewhere in between, at our level, both exist. These arguments also have obvious implications for God and Religion.
And sepaking of God and Religion, I'd like to address and issue of particular importance to Unitarian-Universalists, but really of importance to everybody: the conflict between Secular Humanism and Spiritualism. I do consider myself unabashedly a Secular Humanist, and the definition fits me to a t, yet I'm embarassed by the allergic reactions many Secular Humanists seem to have to mentions of God or anything spiritual. I think embracing the full meaning of "Humanism" REQUIRES an acceptance and respect of spiritualism, for this too is part of the human experience. Indeed, it is one of the greatest accomplishments of the human creativity which Humanists so admire. I'm not asking for us to give up our commitment to secularism, but instead broaden our concept of it to embrace a definition similar to tah expounded by the Dalai Lama: "I call these secular ethics, secular beliefs. There’s no relationship with any particular religion. Even without religion, even as nonbelievers, we have the capacity to promote these things." Secularism, and particular Secular Humanism, should not be exclusionary, but inclusionary.