CC Ādi 4.107
bhrama-maya ceṣṭā, āra pralāpa-maya vāda
In the final portion of His pastimes, Lord Caitanya was obsessed with the madness of separation from Lord Kṛṣṇa. He acted in erroneous ways and talked deliriously.
Lord Śrī Caitanya exhibited the highest stage of the feelings of a devotee in separation from the Lord. This exhibition was sublime because He was completely perfect in the feelings of separation. Materialists, however, cannot understand this. Sometimes materialistic scholars think He was diseased or crazy. Their problem is that they always engage in material sense gratification and can never understand the feelings of the devotees and the Lord. Materialists are most abominable in their ideas. They think that they can enjoy directly perceivable gross objects by their senses and that they can similarly deal with the transcendental features of Lord Caitanya. But the Lord is understood only in pursuance of the principles laid down by the Gosvāmīs, headed by Svarūpa Dāmodara. Doctrines like those of the nadīyā-nāgarīs, a class of so-called devotees, are never presented by authorized persons like Svarūpa Dāmodara or the six Gosvāmīs. The ideas of the gaurāṅga-nāgarīs are simply a mental concoction, and they are completely on the mental platform.