Pythagoras believes that the origin of all things is number, and number is the essence of things. Everything shows the laws of mathematics, the identity relationship of "one", the mutual relationship of "two" and the cooperative relationship among many things of "three", showing the order of numbers. As the origin and essence of things, numbers are inherent in things. Because of the low development of natural philosophy at that time, natural philosophy stipulated that everything had an internal "thing", which was the "origin". Pythagoras believes that number is the source of all things, which means that "number is the inherent reality of all things". Pythagoras believes that numbers exist in reality and in every object. Therefore, numbers are the original elements of things and are attached to things. It's real, realistic stuff. Number is the origin of all things, and it is also the real thing in things. Then, the real thing can obviously be subdivided. For example, "A tree can be divided into 29 leaves, 7 branches, 1 trunk", and many numbers can be subdivided. What about the numbers? This is the problem. Pythagoras believes that since numbers can be applied to objects, there really is such a thing as numbers on objects, so there is much trouble. The smallest unit of mathematics is "1". Pythagoras thinks that 1 is the smallest thing, and he can't divide it, but everything in life can be divided again. For example, if a bean is 1, then the bean can be divided. Is it still there? 1 Is it divisible? This is contrary to Pythagoras' theory in the era of rational numbers. Rational number is rational number, that is, number is an orderly, accurate, harmonious and beautiful explanation of matter and origin. So, a bean is "1". Did you eat 1? Bread with "1" or "1"? Do you eat all of them? "1" still there? Then you can't break this bread and eat it whole. Can I still eat? In reality, it is easy to go wrong if you dig deep at random, but mathematics itself never goes wrong. So numbers can't describe inseparable things. Can they be "primitive"? He's not who he used to be. Why should he explain things? Did he explain why things are always effective, because things are attached to things? This is the unique way of thinking of the Greeks, which is beyond the reach of other civilizations. The problem of eating beans and bread is the common problem of describing things in early mathematics, such as one and many, whole and part, continuity and discontinuity. In the final analysis, it is a philosophical problem, which is directly related to the natural philosophy at that time in eating beans. It always regards the original as something, or something that actually exists in everything.