In the beginning Lord Kapila has said that perfect yoga enables one to transcend the platform of material distress and happiness. How this can be done is explained here: one has to purify his mind and consciousness. This can be done by the bhakti-yoga system. As explained in the Narada-pancaratra, ones mind and senses should be purified (tat-paratvena nirmalam). Ones senses must be engaged in devotional service to the Lord. That is the process. The mind must have some engagement. One cannot make the mind vacant. Of course there are some foolish attempts to try to make the mind vacant or void, but that is not possible. The only process that will purify the mind is to engage it in Krsna. The mind must be engaged. If we engage our mind in Krsna, naturally the consciousness becomes fully purified, and there is no chance of the entrance of material desire and greed.