It looks to me as if 1 and 2 are indeed describing rules of Junto debate, while 3 and 4 (despite the heading that appears in the linked document above the section from which they are taken) are rather describing Franklin's conduct later in life, inspired by his experiences in the Junto.
[EDITED to add:] In the actual autobiography that heading does not appear; where Franklin says what he did "agreeably to the old laws of our Junto" I don't think he is claiming that the practice he describes is itself required by those laws; the term "old" is interesting, but I think the Junto was still active at that time -- Franklin says it was at about the same time as the establishment of the Philadelphia public library, which was ~1730, and elsewhere in the autobiography he implies the Junto's continued operation in the late 1730s.
Even if we take that interpretation, I think 3 and 4 are useful operational expansions of 1 and 2. They're concrete things you can do to implement them.
Huh. Most of the rules make intuitive sense to me. Does it say why they actively prefer to prevent warmth? (something something easier to remain dispassionate?)
I think it's possible that you're interpreting some key words in that provision differently from how Franklin meant them. But I am not very confident either about how he meant them, or about how you are taking them. I think "warmth" may mean "anger" or "heated argument" (and I think you may be taking it to mean "friendliness"); I think "positive" may mean "forceful" (and I think you may be taking it to mean "approving"). The bit about "direct contradiction" seems like evidence for the meanings I am conjecturing; but, again, I am not confident in my guesses about the nuances of 18th-century American English.
I think “positive” may mean “forceful” (and I think you may be taking it to mean “approving”).
This is still a primary meaning in contemporary English:
adjective
- explicitly stated, stipulated, or expressed: a positive acceptance of the agreement.
- admitting of no question: positive proof.
- stated; express; emphatic: a positive denial.
https://www.dictionary.com/browse/positive
That interpretation makes the "I even forbid myself..." part in rule 3 follow more naturally as well.
I'm not sure if this is exactly what he meant, but I can easily see benefits. If the goal is truth-seeking, false positives are as bad as false negatives and bias towards friends is as bad as bias against rivals.
It seems like a good idea not to treat two people having the same assessment of the evidence as further evidence. It's sort of like a policy against groupthink.
(Note: The Junto was a secret society formed by Benjamin Franklin for the purpose of intellectual discourse and business networking. The following is the debate rules they used to maintain an atmosphere of reason.)
Source: Excerpts from the Autobiography Of Benjamin Franklin