There are two approaches that one can take into an argument/debate/discussion, it seems to me. One is to seek victory at all costs. The other is to seek the truth. Let us consider the likely outcomes of these two approaches.
If the reason to debate is to achieve victory, truth is a secondary consideration. The primary concern being winning, there must also be a loser. In order to avoid being the loser, one must be prepared to cling to a losing argument even in the face of truth. It is at this point when the victory-at-all-costs debater may need to engage in some unscrupulous tactics like the personal attack, changing the subject, creating straw man arguments and so on. This kind of debater will sometimes accept a false assertion but think that they have won the debate.
The truth seeking debater seeks truth first and foremost. This debater is willing to accept his opponents argument if it is shown to be true. This debater may lose the debate but will more likely arrive at the truth in the process. In this kind of debate, there really is no loser. It is a win win situation as both participants arrive at the truth.
I see far too many of the win-at-all-costs debaters and too few truth seekers.