Indian logicians laid down rules to regulate the method of
Conducting a debate and also the eligibility of a person.
These rules follow closely the Nyaya system.
A person who doesn't accept the pramanas, prameyas and the distinction between one's own stand and that of the opponent is not eligible for debate.
"na vAde sunya vAdinaha adhikAro anupAyatvAt" (Vedartha sangraha of Sri Ramanujacharya. This mainly directed against Madhyamika Buddhists)
It is futile to hold discussion on phisophic issues with such a person because, in the absence of norms laid down and accepted for meaningful discussion, no truth can be delivery established.
If a person is not eligible for a debate how can anyone enter into meaningful discussion with him?
Whether one is eligible or not for a debate is decided by an impartial person who presides over the debate (Madhyastha)
If the presiding person who presides over the debate is siding without being impartial, discussion should be terminated. In fact, one shouldn't enter into debate with an ineligible person.
The point to be noted is that if a discussion is held with the other party , who is ineligible for the debate, then it amounts to the ineligible opponent being accepted for debate and as such the disputant gains eligibility for debate.
That such a disputant ineligible for debate is to be communicated to him only through a disciple
(Swami Vedanta Desika in Satadhusani khathanadhikara vada)
When two persons or parties having a difference of opinion on a phisophical topic agree to hold a discussion, it is called 'katha' or philosophical discussion.
( Swamy Vedanta Desika in Satadhusani Chapter 4 - " paraspara viruddha vAdinor vyavahAraha katha")
This 'katha' is of three types :
Vada : It is a philosophical discussion whose sole objective is to ascertain the truth by adopting the mutually accepted canons of logic and pramanas. It is not for the selfish purpose of one's own victory.
Kalpa : This is a discussion directed towards establishment of one's own position by refuting the view of the opponent with purpose of achieving one's own victory.
VitandA : This argument is adopted solely to refute the opponent without establishing one's own position.
VitandA is again divided into two
(a) vitarAga vitandA - This discussion is carried without passion for the purpose of right cause.
(b) vijigisu vitandA - This discussion is carried out to merely refute the views of the opponent.
Even those who resort to vitandA type of arguments are required to accept certain principles though the disputants are not concerned with the establishment of their own theories. Otherwise they become ineligible for discussion.
( Swami Vedanta Desika in Tattva Mukta Kalapa Chapter 4 -63)
Gautama , the exponent of Nyaya system , has outlined 21 kinds of fallacies called " nigraha sthanas or points of opponents defeat". ( Nyaya Parishuddhi of Swami Vedanta Desika)
These are aimed at exposing the lack of proper understanding of the topic under discussion. Of these, the most serious defect is not having the capacity to understand the fallacy, and, even if one had such a capacity, not being able to raise any criticism ( asiddhi). The former is known of "jAti" and the later as "chala".
"JAti" is making statement against one's own words (sva-vyAhatA vAk), self - contradictions.
Again this of three types :
(a) yukta tyAgaha - self contradictory statements implying rejection of what is essential.
(b) ayukta grahanam - Acceptance of what is unimportant.
(c) Avisaye vrittih - Attempt to prove what is impossible.
" Chala" means as an attempt to impute a different meaning to the words expressed other than the intended one and on that basis to criticise the argument.
e.g. ' nava kambola yam' actually means the person wearing a new blanket. The word 'nava' also means nine and by attaching that meaning, it is argued that there are no nine blankets but one blanket only. There are various types of 'chalas'
Most important principle to be observed is that in conducting the discussion everyone should accept the pranamas. Else, it will neither help to prove one's own position nor refute that of the opponent. Whatever is said should be authoritative. These are pre requisites of a vada or discussion.
Some other principles are :
The two disputants should be careful about the statements they make.
(A) If one makes a mistake by making a erroneous statement, the other party should bring it quickly it his notice. If, on the contrary the other party is is silent, it will be treated as lapse on his part.
(B) If both make mistakes, then they are allowed three chances each to correct themselves. This is called ' satpakshi' or six chances, three for each. Within the three chances whoever corrects himself earlier becomes victorious. If both don't correct themselves within the three chances , the presiding person will have to suspend the discussion.
( Swami Vedanta Desika in Tattva Mukta Kalapa Chapter 4-66)
(The contents are from book called " Fundamentals of Visistadvaita - Based on Tattva Mukta Kalapa of Swami Vedanta Desika" by author S.M.Srinivasachari)