Uprooting Avidya
The antidote to avidyā is the development of correct knowledge and perception: "wisdom" (Skt.: prajñā; Pali: pañña). This can be achieved by training in ethics, concentration, and logical analysis of reality. More generally, wisdom is developed by following the Eightfold Path.
In a bit more elaborate way, ignorance is the antithesis of correct knowledge and correct perception. The ontological, epistemological, and metaphysical differences between Buddhist schools of practice and philosophy are hotly debated by scholars, both Buddhist and Western; however, philosophically and practically one can assert that all the schools use both concentration (Samatha) and analysis (Vipassana) to negate impossible modes of existence which appear to our ordinary, naive mind during the course of ordinary activity.
In the case of the Theravada, in general, one is analytically negating a permanent, unchanging self or phenomenon using logical analysis and single-pointed concentration. In the cause of the Mahayana, in general, one is analytically negating an inherent, truly existent, or dual self of persons and phenomenon using analysis and single-pointed concentration (see Diamond Slivers and Concentration Training). The object being negated in both cases is a unitary, unchanging, eternal, self-sustaining, self-arising phenomenon which appears (to our naive ordinary day-to-day mind) to provide identity to the experiencer or to the objects of experience. In other words, there appears to be a real "I, me" which sits behind our mind and body somewhere which is having our experiences and is the real "I, me" which makes decisions for the body and mind.
There also appears to be objects and people outside of ourselves who project identities and qualities that we just happen to be there to experience: there seems to be a "real table quality out there" which makes the table what it is. Commonly people would say, "It is what it is." Meaning, that there is something in the object or about the object which makes it what it is, and that the observer (you, me, cat, dog, cockroach, etc.) has nothing to do with that. That type of inherent, unchanging identity is termed Avidya. The misperception of an inherent or unchanging phenomenon and an inherent or unchanging "I, me" allows the mind to generate all sorts of negative emotions (see Kleshas (Buddhism)).
In terms of correct analysis to overcome this mistaken perception, the actual experience which is perceived by all Buddhist is identical: a mere absence or negation of the impossible modes of existence which appear to the conventional, naive mind. However, after the inferential or direct experience of that, when the practitioner returns to a non-concentrated, non-analytic state they are once again privy to philosophical training received prior to that experience. Therefore, one practitioner will describe that experience as being a mere lack of inherent existence, another will say it is a mere lack of true existence, another will say it is an inseparability of mind and reality, and another will say it is a mere lack of permanence/stasis. In terms of correct philosophical language, only one school can be correct, but in terms of direct valid experience all schools may or may not be correct. This is a debate point among the different schools and sub-schools.
Read more about this topic: Avijja