Man has three chief instruments: the Manas, the Buddhi and the senses. Only when these come into union with one another, only when they choose one another, does either of their tattvas come about: the attainment of saṃsāra or the attainment of the Ātma. But the Paramātma saw that Arjuna might have the doubt, "What, joined with what, gives rise to what?", and explained it clearly: "Pārtha! When the Manas joins with the senses, 'the attainment of saṃsāra' comes about; when the Manas comes under the control of the Buddhi, 'the attainment of the Ātma'. To the Buddhi, the power of deciding; to the Manas, only the charge of carrying out the decision the Buddhi has made: that is right governance."