Culture is a combination of material equipment and all kinds of knowledge, people use equipment and knowledge in order to survive. For some purpose, people sometimes have to change their culture. If a person throws away a tool and acquires a new tool, it is because he believes that the new tool is more suitable. This process of change must be a synthesis, that is, his past experience, his understanding of the current situation and his expectations for future results. The past experience is not always a true portrayal of the past facts, because the past facts have changed through the choice of memory; the present situation is not always accurately understood, because the extent to which it attracts attention is often affected by what is at stake; the future result will not always be expected, because it is the product of many forces other than hope and effort. Therefore, the new tool may turn out to be unsuitable for human purpose in the end.
not explicitly mentioned by the author?
The understanding of the current objective situation may not be comprehensive