TL;DR: People reject new ideas for irrational reasons, not just lack of credentials. Asking "Is that your true rejection?" can help, but be careful not to psychoanalyze.
1. Name-calling is weak.
2. Ad hominem attacks are weak.
3. Criticizing tone is weak.
4. Contradiction needs evidence.
5. Counterargument can be convincing.
6. Refutation is strongest, refute the central point.
7. Classifying disagreement helps identify dishonest arguments.
8. Being less mean makes people happier.
This time picked up one of PG's essays.... this one ..
https://paulgraham.com/disagree.html
>output
TL;DR:
1. Name-calling is weak. 2. Ad hominem attacks are weak. 3. Criticizing tone is weak. 4. Contradiction needs evidence. 5. Counterargument can be convincing. 6. Refutation is strongest, refute the central point. 7. Classifying disagreement helps identify dishonest arguments. 8. Being less mean makes people happier.