I am convinced that philosophy and theology cannot be done well without an enduring sense of wonder, but I do not know what wonder is. What is wonder? It will perhaps be helpful to consider undisputed cases wherein wonder is operative. The first case is when the man stands before a great misty mountain and has this sense, this experience. This experience we term wonder. The second case is when a man enters into a great dimly lit Cathedral.
In response to both cases, our alleged man has a sense of the grandeur that lays before him. Wonder here involves a sense of size or complexity, but neither are enough to capture the essence of wonder.
There is also a sense of mystery, of un-plunged depths. The man that stands before the great Cathedral sees immediately a hall of a million meanings. Every part that makes the cathedral the cathedral is infused with a mass of intentions. These intentions lay undisclosed, beyond a single reading. There is here a sense of complexity again, but complexity taken in a different light. It is thus perhaps unsurprising that ancient ruins or ancient cities better evoke a sense of wonder and mystery than a freshly laid concrete high rise. We get the sense of a thousand men dying and a thousand men rising amongst these ruins, and that sense moves us to consider, again, our own microscopic nature.
These observations are getting somewhere but they do not capture the fulness of wonder. Is it no surprise that a concept born of mystery itself remains undisclosed and beyond the powers of short ordered explanation?
Given all of what has been said, an interesting question arises, is there a close affinity between humility and wonder? Can the man that considers himself great enjoy the power of wonder? Wonder may disarm; it may indeed make a great man feel small, but insofar as he considers himself great, even before what is greater, a man cannot, it seems, enjoy the gift of wonder. This is because wonder does involve a sense of grandeur and a man that thinks himself greater than a Cathedral will inevitably see it as a stool for his own foot rather than a throne for the Almighty. Wonder is thus the reserve of the humble, though the great mystery of wonder is that it can turn a great man into a molecule.