I’ll show you my model if you will show me yours. Humans are intellectual model builders. At birth I begin to create an understanding of the world I perceive. I suggest that understanding is an act of creation. Understanding is the product that reason creates, it is the model of my world, as I perceive it. The model starts out as simplistic and chaotic. The rest of my life is an attempt, for reasons of self-interest, to make my model more suitable; in tune with, true to, the world I perceive. Reason is the intellectual faculty that ‘guides’ this endeavor. The better my reason works the better will be my model. The science of reason is Critical Thinking. The more expert I am at Critical Thinking the better my model. The more I recognize this fact the better my chances of building a sophisticated model. The lumber and nails I use for my model is the knowledge I have learned. The greater my knowledge of history the better is my understanding of human nature. The greater my knowledge of philosophy the better my reason functions. The greater my knowledge of science the better my understanding of nature. Mathematics is the science of pattern, what better agent for model building?