4.Know Why
There was an experiment, keeper trained monkeys to drink water from a river and then put out a fire with water from a bucket. Later, the keeper put the bucket on the other side of the river. When there was a fire near the monkey, the monkey would only take water from the bucket on the other side of the river to put out the fire, not knowing to use water from the nearby river. Monkey's understanding of the nature of water is concrete, not abstract. He doesn't know that the water in the river is the same as in the bucket. It is an abstract understanding that water anywhere can put out the fire. So laws and commonality after abstraction are more valuable than concrete things.
We do many things every day, so we need to use many different conclusions. One specific conclusion cannot replace other conclusions and cannot meet our various needs. If we can only deal with one thing, we'll be at a loss if the situation changes slightly in the future. On the contrary, many conclusions can be drawn from an abstract major premise, which can satisfy many kinds of human needs. This major premise is law and commonality after abstraction. Therefore, compared with a specific conclusion, the abstract major premise can better meet the needs of people and has greater value.
Xunzi, the famous Chinese ancient philosopher, said in Li Lun, "Heaven can create living things, but it cannot distinguish things." All natural things are concrete. Nature does not create categories, but only individuals. To distinguish things, we must classify things and find the law of the relationship between the commonness, so as to be widely used in practice. Abstract laws and commonalities exist only in the mind, and the value of subjective things in the mind is far greater than that of objective and concrete things. Philosophy is the most abstract knowledge.
Einstein said, "The most incomprehensible thing about the universe is that it is comprehensible.” In fact, it is easy to comprehend. Because humans are capable of abstract understanding. Abstract knowledge gained from experiments on earth can be applied to the distant universe.