Theories of Knowledge 2: Rationalism and Logic
After discussing the shortcomings of empiricism in the last post, we move on to what might appear to be a solution to the empirical problem of extrapolation but, in fact, predates formal empiricism by about three millennia. Long before empiricism was formalized by Locke, logic was already widely used by the ancient Greek philosophers. Thus, an understanding of rationalism is very important to the understanding of knowledge and information.
The operation of rationalism was very well captured in the character of Sherlock Holmes, Doyle’s protagonist in his most famous detective series. In A Study in Scarlet, Holmes said that “from a drop of water, a logician could infer the possibility of an Atlantic or a Niagara without having seen or heard of one or the other. So all life is a great chain, the nature of which is known whenever we are shown a single link of it.”
According to Wikipedia, rationalism is the belief that “all knowledge, including scientific knowledge, could be gained through the use of reason alone”. Now, as mentioned in my previous post on empiricism, the scientist’s job is to doubt everything. That was what Descartes did, being the Renaissance man that he was. (Descartes was a lawyer, philosopher, mathematician, and theologian.) Assuming nothing, what can we prove? “Cognito, ergo sum”, said Descartes: I think, therefore I am. Assuming nothing, I can prove at the very least that I exist simply because the one who is thinking (assuming is thinking) exists and I am the one thinking.
Of course, after that axiom, Descartes could not prove that anything else exists without assuming that God, or some supreme ”thinker”, also exists. Based on this assumption, Descartes developed formal empiricism and is widely accepted as the father of modern philosophy. He is also widely accepted as the father of modern mathematics and laid the foundations on which Newton, Lorentz, and Einstein would build their theories.
Descartes was a developer of geometry which is a very ancient art that relies purely on rationalism. Geometry was first formalized by Euclid based purely on axioms such as: a point is that which has no dimensions, and a straight line is the shortest distance between two points. Descartes took it further. The Cartesian coordinate system uses the counterintuitive x, y, and z axes that are perpendicular to each other, rather than the bearing, azimuth, and distance away used by the polar coordinate system. Think about this: if you wanted to describe a location relative to you, would you say “5 yards in front, 3 yards to the left, and 4 yards up”, or would you just point (indicating both bearing and azimuth) and say how far away the location is from you? This is the main problem with rationalism. People who cannot handle abstract logic find it very difficult to accept, but those who do greatly appreciate the beauty of its mathematical elegance.
However, counterintuitive as it is, the Cartesian system greatly simplifies problems. Without describing coordinates as perpendicular axes, calculus would never have taken off as quickly as it did. Cartesian algebra and calculus is so simple that high school students can handle them with minimal effort while college students with concentrations in physics, mathematics, or computer science often have great difficulty applying polar algebra and calculus.
Moreover, while real experiments may produce variable results, thought experiments do not. For a long time, people such as Michelson and Morley tried to detect ether which they thought was the medium in which light propagated. They spent a lot of money on finding the best apparatus and a lot of time repeating the experiment to minimize random error, but they could only conclude within a certain standard deviation that they could not find the elusive “ether”. Not too long later, Einstein came along with an explanation that did not even require him to lift a finger in experimentation.
In the Einstein’s Mirror thought experiment, Einstein imagined that he was travelling in a train at the speed of light and looking in a mirror. He asked this question: would there be an image in the mirror since his face and the mirror was travelling at the same speed as light leaving his face? Essentially, if light was like sound, he would not because light would not be able to escape his face, yet it should. Thus, the theory of relativity was born and the laws of classical physics were overhauled without a single experiment.
In fact, later on, when the Rayleigh expedition proved conclusively that the theory of relativity was correct, Einstein was purported to have said that if it had proved otherwise, he “would be sorry for the good lord because the theory is correct”. Such is the confidence of rationalists on their approach, and rightly so. Unlike empirical knowledge, there is no standard deviation or confidence limit on knowledge derived logically from axioms. For any axiom A: if A then B; if B then C; therefore if A then C.
However, back to the problem that Descartes faced after proving that the “thinker” exists, faith is required to prove that anything else exists. I am very tempted to skip ahead and write on faith in the next post but the next two levels, priori and authority, also depend greatly on faith. Therefore, I will be writing on those in my next post.