The Yoga Sutras of Patanjali describe many aspects of yoga, including the mind, ego and consciousness. They delve into areas of the self that many of us do not normally consider. Written approximately 1600 years ago, the simplicity and directness of the sutras make many of these aphorisms even more profound.

In the yoga sutras, yoga itself is defined as the cessation of the movements of consciousness. In other words, a still mind without all of the random thoughts and mind stuff that go around in our heads all the time. Though the definition is simple, achieving a true state of yoga is quite difficult.

Modifications of the Mind

The fifth yoga sutra describes five different modifications of our mental state. All movements of consciousness can be divided into these five fluctuations of the mind. They are correct knowledge, illusion, delusion, sleep and memory.

Correct Knowledge

We obtain correct knowledge, accurate information, from our own direct perceptions. Things that we observe, see and hear fall into this category. Knowledge may also come from things that we deduce or figure out as long as those sources of information are also accurate. Learning through yoga practice that contracting our quadriceps helps to release the hamstrings is one example. We might also gain correct knowledge from authorities on particular subjects; yoga masters for example.


Illusion may also be thought of as incorrect knowledge. Basing conclusions on inaccurate or incomplete perceptions is one way to get wrongful information. Illusions might also be thought of as distortions of reality.


Any knowledge, or perceived knowledge, in a state of delusion is not based on reality. Imagination may thought of as a creative form of delusion. Various mental illnesses are types of delusion, but so are daydreams where our mind roams free. Both delusion and illusion keep us off track when we are pursuing yoga related goals.


We are all familiar with sleep, but usually do not take to time to think about it as a mental state. Sleep may be considered as a time when the mind is without thought or knowledge. Mentally, we are inert and not connected to our senses of perception.


Memory takes us out of the present tense. What we recollect may be based on any of the other states of consciousness, for example, correct knowledge or delusion. Though our memory may incorrectly recall the past, it may also, when used with discrimination, allow us to compare current actions or conditions against previous experiences.

Though all of these five types of mental fluctuations or thoughts can be further broken down into subcategories, the basic headings are a useful way to organize the types of actions that we observe in our minds. Learning to be watchful of our mental condition is just as important in yoga as the physical actions of the asanas. Only when the mind is both absorbed and still are we truly practicing yoga.