Post Author: Bill Pratt
I know this seems like a ridiculous question to normal people, but this is actually a very live and contentious debate among the professors teaching your children at the university. So you need to pay attention to these debates, lest your college expenditures be flushed down the drain!
The classical Christian answer to this question comes from Thomas Aquinas, the brilliant thirteenth century theologian and philosopher. His answer to this question is conveniently summarized for us by another brilliant Christian philosopher, Norm Geisler, in his book about Thomas Aquinas, called, strangely enough, Thomas Aquinas. So how do we come by knowledge?
Aquinas believes that knowledge comes either by supernatural revelation (in Scripture) or by natural means. All natural knowledge begins in experience. We are born, however, with an a priori, natural, innate capacity to know. Everything that is in our mind was first in the senses, except the mind itself.
How do we know something for certain?
Knowing something for certain is possible by means of first principles. First principles are known by way of inclination before they are known by cognition. These include: (1) the principle of identity (being is being); (2) the principle of noncontradiction (being is not nonbeing); (3) the principle of excluded middle (either being or nonbeing); (4) the principle of causality (nonbeing cannot cause being); and (5) the principle of finality (every being acts for an end).
By these first principles the mind can attain knowledge of reality—even some certain knowledge. Once the terms are properly understood, these first principles are self-evident, that is, they are undeniable.
Aquinas believed that all certain knowledge can be reduced to these first principles. Without these first principles in place, no knowledge is possible. In fact, the world becomes completely irrational and incoherent.
So how is reality to be studied? According to Geisler,
Like Aristotle, Aquinas believes it is the function of the wise person to know order. The order [that] reason produces in its own ideas is called logic. The order [that] reason produces through acts of the will is known as ethics. The order [that] reason produces in external things is art. The order [that] reason contemplates (but does not produce) is nature.
Nature contemplated insofar as it is sensible is physical science. Nature studied insofar as it is quantifiable is mathematics. Nature or reality studied insofar as it is real is metaphysics. Metaphysics, then, is the study of the real as real or being insofar as it is being.
It should be incredibly clear from Aquinas’s thoughts (and Aristotle’s) that the modern idea that physical science is the only discipline that produces knowledge is utterly false. Physical science is only applicable to the study of nature “insofar as it is sensible.”
Logic, ethics, art, mathematics, and metaphysics are all separate disciplines from the physical sciences. To subsume these areas under physical science is an error that has profoundly negative consequences for mankind. If physical science is king, then men will be obsessed with technology (what physical science produces). Ethics, logic, art, metaphysics, and even mathematics will all serve technology.
Is that the world we want to live in?