While it is based on principles that any rational person would adhere to, it may be the most complex thing in all of finance. On the other hand, it may not be. It's all Greek to me. A precedent embalms a principle. The Great Principles on which we will build this business are as everlasting as the Pyramids.
Rationalism is an adventure in the clarification of thought.
A good part of the pricing is about sticking a wet finger in the air, and hoping you get it right. Good theories, like Black-Scholes, provide a theoretical laboratory in which you can explore the effect of possible causes. They give you a common language with which to quantify and communicate your feelings about value.