True spiritualism requires surrender in bhakti, not philosophical speculation or material discipline.Listen — Srila Prabhupada Uvaca
Śrī Caitanya-caritāmṛta, Ādi-līlā 7.39–47 — February 5, 1967, San Francisco 670205CC-SAN FRANCISCO [24:12 Minutes] Prabhupāda: ...accustomed to follow the Vedic principles. Just like in Christian religion, those who do not follow the Bible, they are called heathens. Similarly, in Muslim, those who do not follow the Koran, they are called kafirs. Similarly, those who do not follow the Vedic principles, they are called nāstika or mlecchas.
Nāstika means those who do not believe in the Vedic principles; they are called nāstika, atheist. And those whose behavior is not very clean, they are called mlecchas. So in comparison to Hindu mode of living and others in the world, there is very great difference, social sanctity and personal sanctity. So therefore, the..., formerly the mlecchas means the Muhammadan, because they are meat-eaters, they do not take bath daily and there are so many things. So even those persons who were delivered by Lord Caitanya, but the author says that He could not deliver the Māyāvādī, the impersonalist sannyāsī. That means it was easier for Him to deliver the mlecchas, but it was difficult for Him to deliver the Māyāvādīs.
In other words, the author is trying to place the position of the Māyāvādī sannyāsī less than the mlecchas. Less than the mlecchas. So, sabe eḍāila mātra kāśīra māyāvādī [Cc. Ādi 7.39]. [All were converted into devotees of Lord Caitanya, even the mlecchas and yavanas. Only the impersonalist followers of Śaṅkarācārya evaded Him.] Māyāvādī means materialist.
Māyā means this matter, and vādī means those who stick to this principle of material... So there are different kinds of materialists. Because we should always know that up to the point of intelligence, it is matter. First point is the senses, the gross.
The grossest type of materialist is that they are addicted to sense gratification. So this is materialist. And above this, there are mental speculators. They are also materialists, because mind is matter. So the sense gratifiers and the mental speculationist, and those who are trying to reach spiritual perfection by bodily exercise...
Because body is not at all spirit; it is matter. But by intellectually, by making proper adjustment... Just the only benefit of such exercises is to concentrate the mind. The mind is very disturbed.
So that is also materialist. That means jñānī, yogī and karmī. Karmī means those who are working very hard day and night simply for sense gratification. That's all. They are called karmī.