Purity of intelligence (Satva Buddhi) is like ashes, which can neither burn nor be extinguished. It is like that form of the moon, in which the no-moon day has gone and the new moon day has not yet begun. It is like the river Ganges flowing clearly at the end of summer, before the rainy season begins.
Similarly that intelligence is pure, where there is neither desire nor regret, where the attributes of activity and of darkness have been subordinated and which is absorbed in the contemplation of Self. The senses may convey to the mind objectively a good or a bad sensation, but the mind will receive it with equanimity. The mind is indifferent to any immediate loss or gain, as is the mind of a chaste woman, whose husband has gone abroad. The true mark, therefore, of purity of intelligence is, that the mind is directed towards the true form (of Self) and the intelligence has no other purpose except this.
In order to attain his true Self pursues either the path of wisdom or the path of Yoga and in which he completely directs his heart towards this purpose, just as the final offering is given into fire at the end of a sacrifice, just as having bestowed his daughter on a bridegroom of good family, the father is free from anxiety, or just as Lakshmi, the goddess, is devoted to Vishnu. Without entertaining any doubts, to pursue the path of wisdom or of Yoga (activity) is an important attribute.