The Bhagavad-Gita calls on humanity to dedicate body, mind and soul to pure duty and not to become mental voluptuaries at the mercy of random desires and undisciplined impulses.
He who runs to the doctor, vaidya, or hakim for every little ailment, and swallows all kinds of vegetable and mineral drugs, not only curtails his life, but by becoming the slave of his body instead of remaining its master, loses self-control, and ceases to be a man.
In the march towards Truth, anger, selfishness, hatred, etc., naturally give way, for otherwise Truth would be impossible to attain. A man who is swayed by passions may have good enough intentions, may be truthful in word, but he will never find the Truth.