The manas acts with purposiveness

People who have not studied Buddhism always act with a purpose in whatever they do; Buddhist practitioners who have not cultivated their minds to the state of non-action also generally act with a purpose. Which mind possesses this purposiveness? Sentient beings act driven by desire, and their minds all harbor purposes; those who act without desire or seeking, freely according to conditions, are as rare as phoenix feathers and unicorn horns.

The purposiveness and desires that exist before an action is undertaken all belong to the manas. Sometimes, too, the manas' desires and purposes arise through the instigation and instruction of the mind consciousness. Only when the manas has desires does it drive the six consciousnesses to perform bodily, verbal, and mental actions in accordance with its own desires. In the course of their operation, the six consciousnesses also each have their own desires, which in turn influence and transform the manas, causing it to extinguish its own desires or to give rise to new ones.

If someone is not a bodhisattva of vast capacity, not a bodhisattva whose mind is partly or entirely in the state of non-action, and he claims that he acts with no desire and no seeking whatsoever, it is best not to believe him. When such a person comes to approach you, he certainly already has something he seeks and a purpose in mind; the only question is whether that purpose is right or wrong, wholesome or unwholesome.

If the manas had no purpose, He would simply rest and do nothing. Even the Buddha's manas has purposiveness—for the liberation of sentient beings. When the Buddha came to the Sahā world, He came with a purpose; otherwise, why would the Buddha come at all? Some people have purposes they themselves do not know, cannot detect, or deliberately choose not to detect. When the mind consciousness is not subtle enough, it cannot know the manas' hidden desires and purposes.