Unless one is under the shelter of a realized spiritual master, his understanding of the Supreme issimply foolishness” quote from TLC
LA July 13 1971—
Prabhupāda: Unless one is prepared that “I am accepting somebody as my spiritual master. I must accept whatever he says,” if there is any doubt, that I cannot accepthis words verbatim,” then one should not accept him as spiritual master. That is hypocrisy
The 4th regulative principle is–no gambling and no speculation
 Adi 8.15 : PURPORT :—Śrīla Bhaktisiddhānta Sarasvati Ṭhākura comments in this connection that people in general, in their narrow-minded conception of life, create many different types of humanitarian activities, but the humanitarian activities inaugurated by Śrī Caitanya Mahāprabhu are different.For logicians who want to accept only that which is  proven through logic and argument, it is a fact that without logic and reason there can be no question of accepting the Absolute Truth.
Unfortunately, when such logicians take to this path without the mercy of Śrī Caitanya Mahāprabhu, they remain on the platform of logic and argument and do not advance in spiritual life.

However, if one is intelligent enough to apply his arguments and logic to the subtle understanding of the fundamental spiritual substance, he will be able to know that a poor fund of knowledge established on the basis of material logic cannot help one understand the Absolute Truth, which is beyond the reach of imperfect senses. The Mahābhārata therefore says: acintyāḥ khalu ye bhāvā na tāṁs tarkeṇa yojayet. (Mahābhārata, Bhīṣma-parva 5.22) How can that which is beyond the imagination or sensory speculation of mundane creatures be approached simply by logic? Logic and argument are very poor in spiritual strength and always imperfect when applied to spiritual understanding. By putting forward mundane logic one frequently comes to the wrong conclusion regarding the Absolute Truth, and as a result of such a conclusion one may fall down to accept a body like that of a jackal.
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