Vitarka is the hindrances on the path of yoga. Tarka means reasoning. The prefix ‘vi’ expresses opposition, negation, variety, distinction, and so on. Sage Patanjali has used the word vitarka in two different ways. It is used to indicate one of the four varieties of samprajnata Samadhi (profound meditation) (Yoga Sutra I.17).
The four divisions are made according to the nature of vishaya (object of concentration) of the mind. There are four categories of objects such as sthula (gross objects), sukshma (subtle objects), the sense organs and the two basic realities of the self and primordial nature (prakriti).
Four varieties of samapatti or samprajnata Samadhi are recognized according to the four categories of objects used as alambana (support) for concentration of mind.
Vitarka is that variation on samapatti in which the mind is fixed on a gross object like one of the five elements – prithvi (earth), jala (water) or their combinations.
Vitarka samapatti is further divided into two types – savitarka and nirvitarka. The former has a mixture of words, its meaning, and its experience. The latter means experiencing the object alone, without any feeling of self-awareness.
In another sense, Patanjali used the word vitarka to mean the nature tendencies that are the opposite of yamas (five abstinences) (Yoga Sutra II 33-34). The tendencies are himsa (violence), asatya (lies and falsities), steya (stealing), maithuna (sexual indulgence) and parigraha (accumulation of wealth). The five vitarkas do come up in the mind of a student of Yoga and hinder the discipline of abstinence.
Sage Patanjali has recommended the technique of pratipaksha bhavana (acquiring equanimity) for combating vitarkas.