While explaining a fact about charity, St. Thomas pointed out the difference between asking a doctor two questions:
a.) How much medicine do you want the patient to have?
b.) How much health do you want the patient to have?
The right answer to the first is a definite amount, say, 5 ml four times a day for ten days. The right answer to the second question is goes beyond any definite amount – the doctor wants the patient have as much health as his art can induce, and having given that amount he wants to extend the art to give even more.
St. Thomas takes the answer to the second question to be generally true of all ultimate ends, i.e. to take something as an ultimate end is to desire it without measure or limit. Two corollaries:
a1.) Nietzsche’s doch alle Lust will Ewigkeit, “all desire desires eternity” can be read on this axis. If human life has any unity at all and is not merely the disconnected chasing after unrelated goods then any desire demands that there be something that is appropriate to love in an absolutely unlimited way. Nietzsche’s other commitments keep him from making this a cosmological argument. Mine don’t.
a2.) Why can’t the relevant infinite good be “the greatest good for the greatest number”? Because this either articulates some disconnected series of unrelated goods or not.
b1.) Epistemological monisms (viz. Naturalism) demand that abstract rationality be the sole revealer of the real and so be an unlimited good for a rational being. This demands that rational beings understand nothing about the real in times of Dionysian excitement, commitment by vows in the face of the uncertain, awe in the face of the sublime, etc. In fact, the revelation of the real – truth – exists on the one hand in its conformity between concept/hypothesis and the world and on the other hand in its being an absolute and therefore sacred value. Naturalism wants to defend the first notion while being bewildered or embarrassed by the second, even though both dimensions of truth follow from it being the final end of a rational being.
b2.) Naturalism wants a truth without a sacred but which is everywhere thrown open for anyone to judge or prod at.
Why “sacred”? Because the absolute value is available to us only on the condition that we recognize that our knowledge cannot measure it out. As made available it can be true as conformed; as unable to be measured but measuring us it is sacred.