So then we ask, if we do have such a wonderful basic consciousness ,what are all of these attitudes of desire and hatred which bring us suffering? These are adventitious. The defilements appear in the mind due to temporary or adventitious causes and conditions, and do not reside in the very nature of the mind, therefore, they can be removed.

To given an example of this, the protector Nagarjuna says in his Praise of the Element of Superior Qualities:

When a metal garment which has become stained with contaminations

And is to be cleansed by fire, is put in fire,

Its stains are burned but it is not.

Applying this to what is exemplified, he then says:

So with regard to the mind of clear light

Which has the stains of desire and so forth,

Its stains are burned by wisdom’s fire

But its nature, clear light, is not.

Therefore the temporary faults can be purified or removed. The direct antidote to removing these defilements is the wisdom realizing the emptiness of inherent existence. In order for that antidotal consciousness realizing emptiness to be powerful, it is necessary for it to be accompanied by a compassionate method. Therefore, it is necessary to generate wisdom accompanied by compassionate method.

In the sutra system, the union of method and wisdom is posited by the compassionate method and the wisdom realizing emptiness as different entities—one assists the other or is influenced by the other. However, in the mantra system, compassionate method and the wisdom realizing emptiness are posited within the entity of one consciousness, not as different consciousnesses with different entities. They are found within one undifferentiable entity that can be conceptually isolated into different factors, but they are of one entity.

Because of this very powerful meditative stabilization, the union of calm abiding of the mind and special insight can be generated. A special form of this can be generated in mantra. The glorious Chandrakirti talks about the need to engage in a path which is the union of compassionate method and wisdom. Chandrakirti says in his Supplement to the Middle Way (Madhyamakavatara):

The king of the swans, with the vast, broad, white wings of the conventional and the ultimate, moving in front of the swans of beings, goes through the force of the winds of virtue to the supreme far shore of the qualities of the conqueror, Buddha.

via Vajrasattva Meditation and Recitation by His Holiness the Dalai Lama.