Metaphysics and mathematics are not unlike each other. Both are dealing with abstractions that have no relationship with reality. In the case of mathematics, a laboratory is not needed (the reality). Mathematicians can daydream using their abstractions until their hearts are content creating imaginary realities in the example of string theory. Maybe this is why there is no Nobel Prize for mathematics. Maybe Alfred Nobel was under the impression that mathematics for all its elegance is a fiction—but a useful one.
Turning to metaphysics, it is forever weaving a tissue of ideas or concepts by which to interpret reality hoping to unearth its system or at least to shed some light on a possible system by analogy. As such, our thinking turns to what can be described as categorical thinking which is a kind of affirmation process designed to organize our ideas or concepts, universally, about reality. It is with the italicized ‘about’ of reality that metaphysics faces a problem. It cannot enter into direct communion (samadhi) with reality. There is no laboratory, so to speak, for metaphysicians or mathematicians. This is to say, there is no way for them to test whether or not their fictions line up with reality.
Now enters Buddhism. It is about awakening (sambodhi) to reality, that is, ultimate reality. Buddhism is a laboratory with many experiments going on finally culminating with our discovery of true reality. When Siddhartha the Bodhisattva became awakened or a Buddha, he saw ultimate reality—his enlightenment was not framed or built up by metaphysics.
“The Dharma obtained by me is profound, of deep splendor, difficult to see, difficult to understand, incomprehensible, having the incomprehensible as its scope, fine, subtle, the sense of which can only be understood by the wise” (Catusparisat Sûtra).
For those who place a great deal of importance on metaphysics it is difficult for them to conceive just how they can get beyond it to enter true reality (dharmadhatu); to see it firsthand. It is not simply a matter of not thinking or ignoring metaphysics. To go into the Buddhist laboratory is much more than this. For one who decides to do this the path is one of discovery; of looking for something within them that is absolutely real but which at the moment they can’t see. It is like a pure field that if you chance to meet it all the bells and whistles go off in a manner of speaking. Suddenly you know exactly why the Buddha was reluctant to teach it; why he said it was empty, or thatness, the reality limit (bhutakoti), the signless, absolute reality, and fundamental reality.