"If you state an opinion to me in a dogmatic manner, which is in direct opposition to my thought, and you imply there is no room to negotiate, then I must conclude, in order to protect my own self-esteem, that you are wrong and will immediately undertake to prove you are wrong. On the other hand, if you state your opinion as a hypothesis, with evidence of a willingness to discuss and explore, I will most likely undertake to prove you're correct."
In Sandler we use the tactic of OK/Not OK, a theory from Transactional Analysis. This means protecting the other person's integrity, their self-esteem. Selling shouldn't be a game of one-upmanship. The sellers role is to guide the prospect through his or her pain, to paint the outcome they want and to define the basis for a solution that the salesperson can deliver through their product or service.
Selling is a high integrity profession if done right and shouldn't be a battle of wills.
I've trained across 400 segments of the market from defence to office supplies, from a matchmaking service to high ticket IT and Banking solutions. This lesson holds true in all of them. Technical, non-technical, tangible, intangible, product, service, profession, the problems are all the same. The things that vary are the number of zeros behind their problems and the jargon. Learn this lesson well. You are selling to people, and people buy from people they like but above all trust. By and large, they trust people who have listened to them not those who dictate to them.
You're not in sales to get your emotional needs met, you're in sales to go to the bank. Always remember why you're doing it. Stick to your real agenda, don't lose the deal because you want to score points. Remember King Pyrrhus. He won the battle only to lose the war because his army was so badly depleted. Pick your battles. Learn how to fall back.