Thirukkural-On Virtue-Control Of Temper-Kural 302

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Even where it cannot hurt others, anger is bad;
But where it does hurt, there is nothing worse.

If a man loses his temper while dealing with his superior or equal, the exercise boomerangs and causes pain or loss of goodwill to himself; and therefore it is bad. But if he gets angry with those under his control, it hurts those others badly, in addition to creating ill-will on both sides. It is, therefore, much worse. Valluvar would say that for this reason, it is to be construed as the worst of all offences.

The idea of this Kural is that anger in every context is bad. It is, therefore, superior to the practical wisdom contained in the following line of Nanmanikadigai.

"Surukuha sellaa idathuch sinam"
(Naanmani 87)

Obviously Valluvar was master of the very best in human relations.