 On the other hand, Śaṅkara accepts the secondary importance of yogic practices that involve a variety of meditation methods, devotional practices, ascetic austerities, moral psychology, and the development of ethical virtues and action ethics (see Sundaresan 2003 on Yoga in Śaṅkara’s method). They may function as indirect means to liberation. Śaṅkara’s ambivalence towards action is not a contradiction. He recognizes a voluntary element in any knowledge to some degree. One must create the proper conditions to align a means of knowledge. For example, to visually perceive an object one may have to open their eyes and turn their head. Then visual knowledge automatically takes place. Similarly, the Advaitin must possess a prepared mind to recognize brahman. Śaṅkara provides a fourfold set of prerequisite conditions characterizing this qualified student: (1) discrimination between what is transient and eternal; (2) dispassion towards objects of enjoyment; (3) perfecting practices such as the control of the mind and senses; and (4) the desire for liberation (BrSūBh 1.1.1).