Five Modifications of the Mind

The yoga system categorizes the vrittis or forms of thought into five sections:

• Comprehension or Pramana,
• Misapprehension or Viparyaya,
• Conceptualization or Vikalpa,
• Deep Sleep or Nidra and
• Memory or Smriti.

All our thoughts, emotions and psychological states fall within either of these sections. These five are again further subdivided into two mental types:

• Klista and
• Aklista.

While the first type causes afflictions, the next does not. Misapprehension, conceptualization and deep sleep are considered to be the three main causes of various afflictions while the categories of comprehension and memory (of certain kinds) are viewed more positively. These two categories of pramana and smriti are also conducive to meditation and the attainment of kaivalya or detachment from the material world.

Pramana or comprehension is the awareness of one's true state of existence. The three epistemologies or valid means of knowledge for this category are:

• Pratyaksha or Direct Perception,
• Anumana or Inference and
• Shabda Pramana or Verbal Testimony.

The knowledge gained from either sensory or inner perception, inference and verbal authority are all considered to be true knowledge according to yoga.