Considerable turmoil has been generated by a Vatican-related Tweet. It proposed that two plus two equals four in science, but in theology the sum could equal five. This “possibility” of five was not exactly new or even startling, except perhaps for its source. The two-truth theory has its uses, no doubt.
Machiavelli famously proposed that human freedom would be exponentially expanded if at least the prince rid himself of the distinction between good and evil. In effect, he proposed a version of this theory that is usually associated with the Muslim thinkers, Averroes and Al-Ghazali. The “truth” of politics and the “truth” of morality are both true. We affirm that evil should not be done. But sometimes it should be done. In that case, evil becomes good.
The two-truth theory held, in its purest form, that a truth of reason and a truth of religion/theology could contradict each other. But both are still true. The Aristotelian tradition held that this situation could not be the case. One view was right; the other was wrong. Reason cannot contradict reason, be it human or divine.
That is what reason means. A thing cannot be and not be at the same time in the same way in the same circumstances. This is called a “first principle.” It is so called because nothing can be clearer from which to deduce the principle. We affirm that something exists. At the same time, we implicitly deny that it is something else.
The average man may not be carried away by these seemingly esoteric reflections. In truth, they are quite fascinating. Some ancient Greeks and Romans dickered with such thoughts, as did later the followers of Occam. The people who, on a large scale, first utilized the proposition that a truth of reason and a truth of theology could contradict each other were seeking to defend Allah.
Why did Allah need defending? It was because of a book he is said to have written manifesting his mind. The men who developed these notions were pious men. They were sharp enough to see that, in a book said to be revealed, contradictory claims were made. Something had to be done to cover the reputation of the god against evident inconsistencies.
The solution that such thinkers came up with, when spelled out, was remarkable. They did not deny that contradictions existed. They said that Allah could will one thing on Tuesday and its opposite on Wednesday. The latest affirmation is always the binding one but it can change tomorrow. In thinking these notions through, things became ever more complicated.
If the will of Allah could affirm one thing on Tuesday and its opposite on Wednesday, he could do the same thing with all the laws of nature. Since truth is not grounded in logos, but in voluntas, the only way we could know that the sun will arise in the morning is if God wills it and we believe it. He could will that it not come up. These presuppositions mean that we cannot really rely on “nature” for anything.
In this perspective, nobody but Allah does anything. It is blasphemy to suggest otherwise. If we make a fortune one day but lose it the next, in both cases it is the will of Allah. Our enterprise has nothing to do with it. Our skills or lack thereof mean nothing. Science cannot really exist in such a world. No incentive is found to investigate “nature” if it can be otherwise at every instant.
A Christian/secularist version of this theory exists, particularly in moral and political philosophy. Nature is evaporated of any content. The difference between Islam and this western view is not so great when we come right down to it. One theory makes Allah’s will responsible for what goes on, so that whatever happens is Allah’s will. The other theory places the will in the individual person so that he is not subject to any ordered nature, but only to his own will.
The Machiavellian version is simply “What the prince (democracy) wills is the law,” to cite a Roman law adage, later cited by Aquinas. In a conflict of individual and collective will, the latter almost always wins, as Hobbes saw.
Why are two-truth theories proposed? Almost invariably they arise to justify what cannot be justified in reason, including the reason of faith. When some position, said to belong to revelation, can only be justified by denying that the Divinity is bound by reason, by logos, we know we are dealing with the two-truth issue.
Ultimately, the justification of “heresy” always involves, in its logic, the denial of reason. Or to put it the other way around, when we see that what is called “revelation” needs to resort to arbitrary will, divine or human, to justify itself, we know that we have reached incoherence.