Whenever a new idea is introduced that challenges the "conventional wisdom," the keepers of that "wisdom" (and their followers) dismiss it as the "hysterical ravings of a lunatic." It is quite understandable that people don't like to have their most cherished ideas challenged—people, that is, who have invested all their self-worth in what they think (or believe). But such people usually end up having to "eat humble pie" when the ideas of the "lunatic" are proved to be true.
Perhaps the most outstanding example of this is the experience of Christopher Columbus. When he proposed that the East could be reached by sailing West, people thought that was the stupidest idea they'd ever heard. And not just ordinary people. Columbus simply could not convince the power holders of his day to give him the financing he needed to get his hare-brained scheme off the ground—until, of course, he met up with Queen Isabella (certainly a woman ahead of her time). Still, people thought he was crazy. It was only when he returned from what he thought was India, laden with gold and tomatoes and other goodies, that those who called him a lunatic were forced to swallow the humble pie that was surely coming to them.
One thinks also of Copernicus and Galileo. Many great minds of the time—including popes and cardinals—thought that these two men (and others, such a Giordano Bruno) were "all wet" about the Earth moving around the Sun. In fact, according to Jerzy Dobrzycki (in The Reception of Copernicus' Heliocentric Theory), Copernicus was actually called a "lunatic throwing everything into confusion." As for poor Galileo, he was forced to recant what he had written in his book, The Starry Messenger, on pain of death. It took the Catholic Church 400 years to eat its share of humble pie when, in 1992, John Paul II finally exonerated Galileo.
Examples could be multiplied—Einstein was (and still is) often portrayed as the "Mad Scientist," G. K. Chesterton considered Nietzsche to be mad, and so on—but the point is clear: Yesterday's lunacy often becomes today's truth. What was nonsense yesterday makes sense today. How is this possible?
Thomas Kuhn, in his book The Structure of Scientific Revolutions (1962), introduced the concept of the "paradigm shift" to explain how scientific revolutions take place. The concept has come to be applied more widely, even outside the realm of science, and we might use it here to our advantage to explain how something that once was "illogical" can come to be accepted as the truth. A paradigm is a set of assumptions that one uses to judge the world and the things and ideas in it. Based on these assumptions, ideas either make sense or are "illogical." But once this set of assumptions changes or we apply a different set of assumptions (that is, when we shift paradigms), then suddenly what was "illogical" makes sense, since we are not judging it by our old assumptions, but by new ones.
This might be illustrated by the differences between Newton's and Einstein's view of the universe. Newton had a clearly defined paradigm within which he did his science: it was the paradigm of the Clockwork Universe. For him, everything followed certain clearly defined laws, and everything was completely predictable because the laws applied equally everywhere and at all times. The motions of the planets (and other objects in motion) could be calculated mathematically and precisely in such a "clockwork" universe precisely because for Newton the universe operated like clockwork. This was a perfectly good paradigm for Newton's time. But Einstein came along and started talking about time being the fourth dimension, and about time dilation, and about two events being simultaneous or not simultaneous at the same time depending on your point of observation, and so on. None of this made sense in Newton's Clockwork Universe paradigm. Einstein not only introduced new ideas, but he changed the paradigm within which these ideas were to be judged. In Einstein's universe, clocks can go faster or slower depending on the speed at which they are travelling. Clearly, Newton's Clockwork Universe paradigm was not adequate to deal with such relativistic effects. In Einstein's new "Relativity" paradigm, everything he said made sense. Once we accepted Einstein's Relativity paradigm, what was once illogical under the old Newtonian paradigm immediately became logical and made perfect sense.
It might be added that quantum physics subsequently introduced another new paradigm that made it necessary to rethink some aspects of Einstein's paradigm. It should be noted that quantum effects do not make sense in Einstein's paradigm, and this is largely why Einstein himself rejected quantum theory. At the top of his list of objections to quantum theory (which he published in a paper in 1935) was the principle of nonlocality, which he derisively called "spooky action at a distance." Great scientist that he was, Einstein was not immune to the name-calling game. He didn't exactly use the words "lunatic," or "hysterical" or "raving"—but his word "spooky" does the job just as forcefully: it shows that he considered nonlocality a whole bunch of nonsense, on the same level as spooks (or ghosts). Nonlocality has since been demonstrated experimentally, and Einstein's objection has been proved to be wrong. Sadly, new paradigms turn old ideas on their head and make fools of us all—even geniuses. But they also—not so sadly—advance our understanding of the universe and our place in it.
So, what is the point of all of this?
The point is that our "rationality" and our "logicality" are only as good as our paradigms. One can choose one's paradigm and stick to it (as Einstein did: he refused to accept the quantum paradigm), or one can be open to new ideas and be willing to switch paradigms easily without getting hung up on any one single paradigm.
We can also apply the notion of paradigm shift to rationality itself. Many people who consider themselves "scientific" are locked into a "Rationality" paradigm and have little sympathy for any other kind of paradigm. The time has come for such people to make a paradigm shift. In this new paradigm, rationality and irrationality go hand in hand: they are a pair of conjoined twins—you can't have one without the other. The world will look very different once this new paradigm is accepted. In fact, it will look more like it really is.