Śyāmasundara: Leibnitz believed that truth could be represented by symbols and made into an exact science, a mathematical science of symbols. He founded the school of symbolic logic.
Prabhupāda: What is that, symbol? What is the symbol of a good man, and what is the symbol of a bad man? We have got the symbol. If one is Kṛṣṇa conscious, he is good man. If he is not, he is bad man. That is our symbolic representation.
Śyāmasundara: He is talking more about mechanistic truths, scientific truths, laws of nature...
Prabhupāda: But this is also scientific truth. Just like, according to Vedic scripture, this black body is a sign of sinful life. Therefore brāhmaṇas are called śukla. Brāhmaṇas are fair complexioned. Still it is said if a brāhmaṇa is black, then he is not a real brāhmaṇa born. Kalu-ban means black man. Black brāhmaṇa is to be understood that his father is not real brāhmaṇa. He is born of somebody else, but he is known as brāhmaṇa. Similarly a śūdra, if he is fair-complected, he is also not real. Kalba kata śūdra bete mussulman. Muslim, if he is a dwarf, he is not real Muslim, because Muslims from Afghanistan are very tall. And kaṅki chale, the son of a prostitute, and puṣṭi putra, adopted son, all of them are rascals. Puṣṭi putra, adopted son, he gets money because a rich man, when he hasn't got a son, he takes somebody else, adopted son, and he gets money for nothing and spends like anything. We have seen it in London. One Mr. Sil, he got immense money, and he died a penniless street beggar. And he was an adopted son. I have seen it. His only business was how to spoil his adopted father's money. And we have seen, he was such a rich man, died a street beggar. This I have seen.
Śyāmasundara: Leibnitz says that there are two classes of truth.
Prabhupāda: What are the symptoms of truth? That he has not explained.
Śyāmasundara: Yes. He divides it into two classes. One is there are logically necessary principles, the truths of reason as innate knowledge, just like the three sides of a triangle equal 180 degrees. That is innate knowledge, or logically necessary truth. This is also called a priori knowledge, or knowledge that exists independently. Then he says that there is knowledge acquired by experience, or a posteriori, accidental knowledge—just like snow is white, but it could be red; it's possible that it could be red—this type of truth which comes from our experience but it's accidental and it is not necessary.
Prabhupāda: So real truth is that God has got a plan, and one who knows it, that is real truth. One who hasn't got to be taught by another man but by nature, he knows it; that by nature he knows it, that is a symptom of his life, true life. And one who does not know it, that is not. That is explained in Caitanya-caritāmṛta, nitya siddha kṛṣṇa bhakta. That truth is there already, but he has forgotten it. Therefore by this propaganda of devotional service, chanting and hearing, he simply revives the truth. The truth is there, that I am eternal servant of Kṛṣṇa. Therefore the conclusion should be anyone who is cognizant of this truth that I am eternal servant, that is symptom of this truth. There is no other symptom. That is the symptom of truth, that is the symptom of goodness, all good qualities, everything good. He is good by nature. The living entity, he is part and parcel of the supreme good. But by his material association he has become bad. So again he has to draw it to goodness by this propaganda, Kṛṣṇa consciousness. That is our business.