One should not even think harm of any kind. To contemplate evil is as bad as committing it in action. Contemplation is not only a preparation for activity but is the seed of the latter. May there be friendliness instead of enmity, love instead of hate, is the motto of Yoga. By love we attract things and by hatred we repel them.
Love attracts love, and hatred attracts hatred.
Ahimsa has always been regarded as the king of virtues and every other canon of morality is judged with reference to this supreme norm of character and conduct. The ego tries to work out its likes and dislikes by various methods, one of them being the uttering of falsehood in order to escape opposition from others. The insinuating of falsehood in society is regarded as a vice. Satya or truthfulness is another virtue. Truthfulness mitigates egoism to some extent.