Cite sastra to support your statements.
According to Bhagavad Gita 17.15 there are two essential principles in discussing sastra. One is to speak pleasantly (see Principle 9), and the other is to cite sastric evidence:
“The process of speaking in spiritual circles is to say something upheld by the scriptures. One should at once quote from scriptural authority to back up what he is saying. At the same time, such talk should be very pleasurable to the ear. By such discussions, one may derive the highest beneﬁt and elevate human society.” Bg 17.15 purport
Questions / My lights:
1. What are the different kinds of evidence?
There are broadly speaking four types of evidence that can be used: pratyaksa (direct perception); sabda pramana (evidence from the Vedic statements); anuman (logical deduction); and aitihya (historical). Of these the most authoritative is sabda pramana:
“Pratyaksa, direct sense perception, and sabda-pramana, evidence from the Vedic statement, and anumana, aitihya, historical or hypothesis. So out of all evidences, the evidence which is called, derived from Vedic statement, that is accepted as most authoritative.” Lecture on Bhagavad-gita 2.20-25 — Seattle, October 14, 1968
“srutih pratyaksam aitihyam anumanam catustayam
pramanesv anavasthanad vikalpat sa virajyate
Vedic literature, direct perception, history and hypothesis are the four kinds of evidential proofs. Everyone should stick to these principles for the realization of the Absolute Truth.”
Madhya 9.362 purport
2. Of the different types of evidence, which is the most important?
“Pratyaksa, aitihya and sruti. Pratyaksa means direct perception. Direct perception, that is evidence. People with poor fund of knowledge, they want direct perception of everything. That is not possible. Direct perception of everything is not possible. Therefore aitihya. Aitihya means historical, historical, parampara, hearing, traditional. And the next first-class evidence is sruti. Sruti means to hear from the authority. That is sruti. Just like the example we have several times cited here that the evidence “Who is my father?” that evidence is to hear from my mother. That’s all. There is no other evidence. The mother says that “This is your father. He is your father.” This is sruti, hearing from the mother, authority. And we have no other authority to understand father. Similarly, we have to understand our supreme father from the sruti mother, Vedas mother, mother Vedic mother. We have to accept Vedas as mother, sruti.” Lecture on Sri Chaitanya-caritamrta, Madhya-lila 20.318-329 — New York, December 22, 1966
“In the parampara system, when the questions are bona fide the answers are bona fide. No one should attempt to create or manufacture answers. One must refer to the sastras and give answers according to Vedic understanding. The words yatha-srutam refer to Vedic knowledge. The Vedas are known as sruti because this knowledge is received from authorities. The statements of the Vedas are known as sruti-pramana. One should quote evidence from the sruti — the Vedas or Vedic literature — and then one’s statements will be correct. Otherwise one’s words will proceed from mental concoction.” SB 7.13.23 purport
“So sruti-smrti-pramana — citing evidence from the Vedas and the corollary literature — is the only method for making a spiritual statement. You have to take it.” Civilization and Transcendence chp 5: Eternal Truths vs. Everyday Realities
“And whenever there is argument on some point, one has to give reference from these Upanisads. If one can give reference from the Upanisads, then his argument is very strong. Sabda-pramana. Pramana means evidence. Evidence… If you want to gain in your case… Just like you have to give very nice evidence in a court, similarly, according to Vedic culture, the evidence is pramana. Pramana means evidence. Sabda-pramana. There are three kinds of evidences accepted by the learned scholars in Vedic culture. One evidence is pratyaksa. Pratyaksa means direct perception. Just like I am seeing you, you are seeing me. I am present, you are present. This is direct perception. And there is another evidence which is called anumana. Suppose in that room, and I am coming just now, I do not know whether any person there is or not. But there is some sound, I can imagine, “Oh, there is somebody.” This is called anumana. In logic it is called hypothesis. That is also evidence. If by my bona fide suggestions I can give evidence, that is also accepted. So direct evidence, and, what is called, hypothesis or suggestion evidence. But the strong evidence is sabda-pramana. Sabda, sabda-brahman. That means Vedas. If one can give evidence from the quotation of the Vedas, then it has to be accepted. Nobody can deny the Vedic evidence. That is the system.” Lecture on Bhagavad-gita 2.8-12 — Los Angeles, November 27, 1968
“Therefore learned scholar, when he speaks something, he gives evidence from the Vedas, sruti, sruti-pramana. That is the best evidence. Go on.” Lecture on The Nectar of Devotion — Vrndavana, November 13, 1972
“Scripture means the four Vedas, the Upanisads and the Puranas. Having emanated from the breathing of Krsna, they constitute perfect knowledge and authority. Particularly in spiritual matters these must be referred to as the final proof. Because the material senses of man, characterized by the four faults of karana-patava (limited perception), bhrama (illusion), vipralipsa (desire to report something other than what is perceived) and pramada (inattention of the senses), cannot possibly perceive anything beyond the material level of unconscious matter, the spiritual realm would be unapproachable without the aid of Krsna. Therefore Krsna has given the four Vedas, which are beyond the four faults of the senses, and by these alone can man progress towards the spiritual goal.” Harinam Cintamani: Chapter 7 – Criticism of Scripture
3. What if the sastric evidence is confusing?
When the sastric evidence is confusing, we can take guidance from the mahajana. As I understand it, the universally accepted mahajana in ISKCON is our founder acharya, Srila Prabhupada. So his purports, lectures etc also count as sastric evidence because they illuminate the meaning of the sastra:
“Sri Chaitanya Mahaprabhu then assured the brahmana, “Have faith in My words and do not burden your mind any longer with this misconception.”
This is the process of spiritual understanding. Achintya khalu ye bhava na tams tarkena yojayet: “We should not try to understand things beyond our material conception by argument and counterargument.” Maha-jano yena gatah sa panthah: “We have to follow in the footsteps of great authorities coming down in the parampara system.” If we approach a bona fide acarya and keep faith in his words, spiritual realization will be easy.” Madhya 9.196″ Madhya 9.196 purport
4. Is it not offensive to ask a senior devotee, or one’s guru, for sastric evidence?
My experience is that some devotees feel it may be offensive to ask a speaker for evidence. It seems to suggest we don’t trust their integrity. But in Jaiva Dharma we hear Vrajanatha asking his revered guru, Raghunatha dasa Babaji to give him sastric evidence. As I understand it, it is the duty of the guru (siksa or diksa) to train the disciple in sastra, so it is not offensive if we ask them to teach us by giving us the sastric evidence. Below I cite the relevant passage from Jaiva Dharma as given in both translations that I have:
Vrajanatha asks Raghunatha dasa Babaji:
“Master, please cite a few verses from the Vedas to substantiate this sloka.” Jaiva Dharma; Brhat Mrdanga Press; pg 265 (chp 17)
Same section as translated in the Gaudiya Vedanta Publications version of Jaiva Dharma; pg 384:
“Vrajanatha: I would like to hear some evidence from the Vedas to verify this.”
Direct perception and logical conclusion are only acceptable as evidence when they are connected to sastra or supported by sastra:
“Vrajanatha: Do pratyaksa and other pramanas have no value at all as evidence?
Babaji: What means do we have to gain knowledge of this material sphere, except through direct perception and other pramnas? Nonetheless, they can never give knowledge about the spiritual world (cit-jagat ), for they cannot enter into it. That is why the Vedas are certainly the one and only pramana for gaining knowledge about the cit-jagat. The evidence gained from pratyaksa and other pramanas is only worth considering when it follows the guidelines of the self-evident Vedic knowledge; otherwise its evidence can be discarded. That is why the self-evident Vedas are the only evidence. Pratyaksa and other pramanas can also be accepted as evidence, but only if they are in pursuance of the Vedas.” Jaiva Dharma; chp 13, pg 288-289 from Gaudiya Vedanta Publication version.”
5. What if the evidence from Srila Prabhupada’s books, lectures, letters and conversations contradict each other?
In their book, Our Original Position, the GBC suggest that Srila Prabhupada’s primary evidence is his books, then his lectures because both these were meant for everyone. They suggest that conversations and letters were meant for private individuals therefore they are secondary to his books and lectures:
“Here it should be noted again that statements made in Srila Prabhupada’s letters cannot override those in his commentaries. His books are mostly commentaries on recognized authoritative works in our line. They are sastra-either sruti or smrti. His commentaries are to be regarded as primary evidence. His letters and other statements are secondary evidence. Books are for everyone and letters and conversations are personal. To be accepted as absolute, the philosophy in his letters must follow the siddhanta in his books, and not the other way around. If he made statements in his letters that do not follow the siddhanta, those must be considered as his strategy for preaching.”
“The conclusion is that in his letters and conversations Prabhupada used a preaching technique, whereas in his books, which are the primary evidence in all matters of the philosophy, he states the true siddhanta.”
“Since these lectures are not merely “personal” but rather public discourses on sastra, giving the purports to revealed scriptures….”
6. What if you don’t know any sastric evidence?
In our home discussions we will frequently spend 10 – 15 minutes researching the Vedabase for evidence. We have purchased a Vedabase which is an excellent investment, and which I find much easier to use than the on-line Vedabase. Much better to spend some quiet time researching evidence then to endlessly speak from our mental concoction. This practice is a very effective way of ensuring we do not deviate from guru and sastra.
When we can’t find any evidence, we will write our question in a file we have especially for our sastra discussions. Then when we meet with senior devotees, we take our question book with us and ask for help finding conclusive answers. I also often post my questions on Facebook asking other devotees who I know like to study sastra if they can help me find any evidence.
I have also started a Facebook group called Sastra Discussion which is especially meant to help devotees to find evidences. Hopefully as a community we can gradually begin to help each other become better educated in the spiritual science. We should be a resource for each other; helping each other to find evidence from sastra. Senior devotees are our best resource to find evidences as they are well versed in sastra.