Only disagree reasonably. There is no value in disagreement if you know that you are wrong. The priority should be knowledge, not to put the other person down. One should be prepared to agree as well as disagree.
Avoid disagreeing hopelessly, anyone can find common ground. In navigating disagreement be mindful of your emotions, and distinguish between genuine knowledge and mere opinion. Very few claims are absolute, self-evident truths. Resolution can only occur when claims are defended with reason.
How to read a book by Mortimer Jerome Adler, Charles Van Doren Criticizing a Book Fairly The Importance of Suspending Judgement