"is thinner than hair and sharper than sword", is the same moral moderation.

"is thinner than hair and sharper than sword", is the same moral moderation. [^1] Now, we shall see from where these quadruple principles have originated?

Ethics scholars say in reply: man's soul has three powers: 1- Power of perception and distinction 2- Power of acquiring benefit or "attraction" and in the other word "desire" (in its general sense) 3- Power of loss repulsion or "repulsion" and in the other word "anger" Moderation in each of these powers forms one of the moral virtues, which are respectively, called wisdom, chastity and bravery.

And when two powers of desire and anger are under control of distinction and perception power, justice is achieved. In other words, balance in each of the above triple powers is considered as a virtue, but their combination with each other, that is desire and anger being controlled by perception power, will be another virtue.

It often happens that a man is brave and for example, is not afraid unduly in the battle field, but this bravery may be utilized in a wrong way, like fighting for little and worthless objectives, and this is bravery but not justice. But if this bravery is applied for a high and intellectual objective and mixed with wisdom, justice is achieved.

Studying and criticism The principles mentioned by previous scholars for morality (good and bad) and described in the foregoing discussion are not perfect, although they may seem interesting: 1- There are some good moral habits that placing them in one of the above quadruple principles seems difficult.

For instance, philanthropy, self-sacrifice and self-devotion, can hardly be included in "chastity", because it is possible that an individual's desires are moderate, while he lacks self-sacrifice, self-devotion and philanthropy. That is to say he neither aggresses to the rights of others, nor desires their loss, but at the meantime does not have any self-sacrifice and self-devotion. Moreover, optimism could not be included in "wisdom", because "optimism" differs with "correct distinction".

Perhaps insisting on this quadruple division is caused by the ideology of the ancients who assumed most of world's issues based on the number four, and considered four things as the main elements, and divided body's components and temperaments into four. They considered four diseases as the principles of physical diseases, and assumed one of four temperaments for all medicines. While today it is certain for us that none of these quadruple divisions are correct.