Lord Caitanya protested against misinterpretations of the Upaniṣads, rejecting any explanation which did not give their direct meaning. The direct interpretation is called abhidhā-vṛtti, whereas the indirect interpretation is called lakṣaṇā-vṛtti. The indirect interpretation serves no purpose. There are four kinds of understanding: (1) direct understanding (pratyakṣa), (2) hypothetical understanding (anumāna), (3) historical understanding (aitihya) and (4) understanding through sound (śabda). Of these four, understanding from the Vedic scriptures, the sound representations of the Absolute Truth, is the best method. Traditional Vedic students accept understanding through sound to be the best.
The stool and bone of any living entity are considered to be impure according to the Vedic literature, yet the same Vedic literature asserts that cow dung and conch shells are very pure. Apparently these statements are contradictory, but because cow dung and conch shells are considered pure by the Vedas, they are accepted as pure by the followers of the Vedas, without argument. If we try to understand the statements by indirect interpretation, creating some hypothesis, then we challenge the evidential authority of the Vedic statements. In other words, Vedic statements cannot be accepted according to our imperfect interpretations; they must be accepted as they are. If they are not accepted in this way, there is no authority in the Vedic statements.
According to Lord Caitanya, those who try to give some personal interpretation to Vedic statements are not at all intelligent. They mislead their followers by inventing their own interpretations. In India there is a class of men known as Ārya-samājists, who say that they accept the original Vedas only and reject all other Vedic literature. The motive of these people, however, is to give their own interpretation. According to Lord Caitanya, such interpretations are not to be accepted. They are simply not Vedic. Lord Caitanya said that the Vedic statements of the Upaniṣads are like sunlight. Everything is clear and very distinct when it is seen in the sunlight; the statements of the Vedas are similarly clear and distinct. The Māyāvādī philosophers simply cover the sunlight with the cloud of their misinterpretation.