Theology means thinking critically about revelation and thereby participating in the eternal discussion, as opposed to thinking critically while unplugged from revelation. Theology only appears constraining if the principle of revelation itself is dismissed, and if it is a mistake to dismiss it, doing so is as constraining as revelation says the world of thought is. The principle underlying the notion of revelation is that comprehensive knowing cannot be arrived at without grace. The finite will know the infinite only on the infinite’s terms, not otherwise. Faith (sraddha) is rooted in this premise.
I see no reason why the faithful as defined above cannot reason their way into a contemporary expression of spirituality that embraces essential tenets of a particular tradition and leaves behind that which is nonessential.
It is not adherence to a central text that is the problem, its the manner in which one adheres to it that determines whether one’s adherence is liberating or confining.
One can think critically and come to a speculative conclusion that there is no ontological standing to revelation, but that does not make it so. One can question revelation or one can accept its proposed ontological status, but the latter need not be arrived at by something less than critical thinking in every sense of the term.
If fundamentalism is a “system for understanding the world” then fundamentalism is not limited to religious thinking. Scientism comes to mind. Dawkins as well. The idea that “intratextuality” limits outside influence upon the system only holds if or to the extent that the central text does not invite self criticism and seeks to limit outside influence. Not all religious texts do this.
Both the Bhagavata and Caitanya Caritamrta properly understood invite criticism and critical thinking and they could very well be considered an exercise in critical thinking intended to foster the same, especially when viewed in consideration of the cultural context in which they originally appeared. One needs to catch the spirit of the text. It is a particular brand of practitioners that seek to limit outside influence even when the text explicitly teaches otherwise: to see God in everyone and everything; to universalize the deity; to listen to nature and love her that she might share her secrets.
Fundamentalist practitioners interpret religious or secular texts that their tradition is centered around in a particular way. Look at Marxism and the Communist Manifesto and how it has been interpreted and expressed. Is there communist fundamentalism? Is there critical thinking fundamentalism?
As for mystics making meaning, they certainly do. Again, they also question the value of critical thinking unto itself for good reason. Reason has been on the altar for quite some time now with no solution at hand. Then again, is it not critical thinking to question critical thinking unto itself as a means to wisdom? Is life ultimately rational? Ask the electron. What does love have to do with it? Moreover, mysticism is open to everyone.
Theological innovation can come at a great cost that defeats its purpose. The trick is to be innovative and survive or to remain spiritually vital and viable. Furthermore, religious fundamentalism is better known in Gaudiya terms as a kanistha adhikari orientation to the tradition, which is for the most part a necessary phase through which one must pass and realize that the nature of authentic spiritual life is that it is challenging, rather than being an excuse for not having to think.