Human history contains evidence that peoples such as the Pharaohs and the people of China and India withstood the hurricanes and transformations of time, and maintained their entity over the centuries. They did not appear or become extinct, but they persisted and subsisted, during which they maintained a character of strength, withstanding adversity, and did not yield to defeat or submit to annihilation.
In the world of thought, similar to these nations, you find philosophical doctrines that have moved over time, and have remained alive and young from their birth until now. These are eternal doctrines similar to the world of thought. Those nations in the world of humanity.
As for the doctrine of pleasure and pain in the philosophy of morals, it was fixed and developed over the centuries. It emerged from basic ideas in the doctrine of Socrates, then it returned to Greece and was formed in one form, then in the Alexandrian school in another form, and it began to move through the ages, and it was worn by benefit instead of pleasure.