Shaykh ul-Islām Ibn Taymiyyah رحمه الله said:
“Insulting, slandering, and being aggressive during a discussion are tricks of those who are weak and a commodity of those who are bankrupt (in ‘ilm). Verily, refutations based upon insults and intimidation, everyone has the capability of doing that.”
[Majmū’ al-Fatāwā, 4/186]