My Dear Chaturbhus,
Please accept my blessings. I am happy to receive your nice letter of January 10, 1972, and I am pleased to note that you are asking very intelligent questions. that is natural position for the neophyte devotee who is sincerely seeking to understand what is the Absolute Truth. So I am very much engladdened to hear that you are very intelligent boy, like your father, and that your whole family is advancing in Krishna Consciousness. May Krishna give you all blessings.
Lord Caitanya met Moulana in Sara, U.P., not at Allahabad. His process was to take a quotation from the Koran and convince the Moulana that Krishna Consciousness or pure love of Godhead in mood of selfless devotional service is the ultimate goal of life.
As for the difference between mental speculation and philosophical speculation, we take it that everything is known by the psychological action of the mind, so that philosophical speculation is the same as mental speculation if it is merely the random or haphazard activity of the brain to understand everything and making theories, "if's" and "maybe's." But if philosophical speculation is directed by Sastra and Guru, and if the goal of such philosophical attempts is to achieve Visnu, then that philosophical speculation is not mental speculation. It is just like this: Krishna syas in Bhagavad-gita that "I am the taste of water." Philosophical speculation in the accepted sense then means to try to understand, under the direction of Sastra and Guru, just how Krishna is the taste of water. The points of Bhagavad-gita, though they are simple and complete, can be understood from unlimited angles of vision. So our philosophy is not dry, like mental speculation. The proper function of the brain or psychological activity is to understand everything through Krishna's perspective or point-of-view, and so there is no limit to that understanding because Krishna is unlimited, and even though it can be said that the devotee who knows Krishna, he knows everything (15th Chapter), still, the philosophical process never stops and the devotee continues to increase his knowledge even though he knows everything. Try to understand this point, it is a very good question.
Lord Caitanya may have long hair in his early grhastha life, but that does not mean that we should imitate Lord Caitanya. Caitanya also had shaven head and sikha. The important thing is that we follow the regulative guidelines as laid down by great saints and acaryas in our line, and so it is recommended that we wear clean-shaven heads. but there is no hard and fast rule in this respect. If it is practical to grow hairs out, that can be done. But it is not that we may imitate Lord Caitanya by growing big hairs.
Hoping this will meet you in good health and happy mood. Your father is serving nicely in Delhi by printing our books and magazines in Hindi language, and I am very much pleased with him also. Now you protect your good mother and brothers and sisters, help them to advance more and more in Krishna Consciousness by holding chanting in your house regularly daily and by having altar. If you become very serious to have the ultimate satisfaction of life, then I think that you will practice this KC process very enthusiastically and be successful in all respects.