Patañjali’s definition of yoga is given with great precision in the second aphorism of the Yoga Sūtras: **“Yogaḥ citta-vṛtti-nirodhaḥ.”** This brief statement is often rendered as “Yoga is the cessation of the fluctuations of the mind” or “Yoga is the cessation of the fluctuations of the mind-stuff.” In this formulation, *citta* refers to the mind or consciousness, *vṛtti* to its various modifications or fluctuations, and *nirodha* to their cessation, restraint, or stilling. The definition is both concise and profound, pointing not to an external activity but to an inner condition of consciousness.

This teaching presents yoga as a disciplined process through which the restless movements of the mind are gradually brought under control and ultimately stilled. When the modifications of the mind are restrained, the surface turbulence of thought and reaction subsides. In that state of mental stillness, the true Self, or *puruṣa*, is no longer distorted by the play of mental activity and can be realized in its pure form. Thus, yoga here is not merely a set of techniques, but the very state in which consciousness is freed from its habitual patterns and fluctuations.

Patañjali’s definition therefore encompasses both method and goal: the systematic restraint of mental activity and the resulting state of clarity that follows. Yoga, in this sense, is the path of moving from distraction to stillness, from fragmentation to an undisturbed awareness. By emphasizing the cessation of mental fluctuations, the aphorism directs attention to the inner work required for genuine spiritual insight, where the mind becomes a transparent medium rather than a source of distortion.