The equilibrium between desire and necessity is kept "by suppressing the desire in accordance with the endurance level". The endurance level is one of a person's HSPs (see Recognizing a person's HSPs, at the start of this part): the amount of societal stress that a person can bear without being psychologically depressed. In RESPECT IS NOT COSTLY, THE INGREDIENTS ARE UNIVERSAL, it is "the endurance level that decides how far one can suppress one’s own needs", and "endurance sets its limit".
How a person comes to know it. Step by step, "by holding back a desire a little at a time and noticing how far he can go without falling into psychological stress", "along with the advice of his sincere relations".
From The performance curve.
