Although there is no material contamination when one attains the stage of Brahman realization, in that stage one is still not perfectly pure because there is no positive engagement in spiritual activity. Because it is still on the mental plane, it is external. The pure living entity is not liberated unless he is completely engaged in spiritual activity. As long as one is absorbed in impersonal thoughts or in thoughts of the void, one's entrance into an eternal, blissful life of knowledge is not complete. When spiritual knowledge is not complete, one will be hindered in his attempt to cleanse the mind of all material variegatedness. Thus impersonalists are frustrated in their attempts to make the mind void by artificial meditation. It is very difficult to void the mind of all material conceptions. In the Bhagavad-gītā (12.5) it is stated that those who indulge in such impersonal meditation find it very difficult to make spiritual advancement. In addition, whatever state they do attain is not complete liberation. Therefore Lord Caitanya rejected it.
After his fourth proposal was rejected, Rāmānanda Rāya said that devotional service rendered without any attempt at mental speculation or cultivation of knowledge is the highest stage of perfection. To support this view he gave evidence from Śrīmad-Bhāgavatam (10.14.3), wherein Lord Brahmā tells the Supreme Personality of Godhead: