In any given discussion where two parties differ strongly on a particular point, one or both parties may attempt to persuade the other by means of argument, in order that they will both agree. This is in fact not usually successful, but that doesn't stop us from trying; when it is successful, we talk of the opposing party having 'changed their minds'. But can we in fact change someone's mind, and, more interestingly, are we in fact trying to?
At first glance, the answer seems an obvious 'yes' to both questions: we disagree, I want to make us agree, and if I succeed, what has happened, if not a change of position from that originally held? It seems impossible for there to be any other explanation. But there is. In actual fact, when one tries to persuade another to agree, one is in fact not trying to change the other's mind in any sense; quite the opposite, in fact. Rather, the whole process of persuasion relies on the other not changing their mind, since any such change would be disastrous to the persuasion.
So what is persuasion, then, that it seeks to create agreement where disagreement once stood, and to do so somehow without a shift in position? Persuasion is in fact an attempt by one person to show another that in fact no disagreement exists in the first place, and the disagreement that exists stems from an erroneous judgement. Think about it: when you want to persuade someone, what do you do? You start from a common point of agreement, and then attempt to show that if you hold this initial point on which you both agree, then it is necessary for you in fact to agree on the matter at hand. Your opponent in turn tries to do the same to you.
The crucial point in persuasion is the point of agreement from which you start. Your whole argument is reliant on the belief that your opponent will not 'change his mind', and end up disagreeing on the starting point. Your persuasion relies on the belief that as long as you both agree, it will end up that you both in fact agree on the matter at hand also.
Persuasion, then, is about saying "No, you don't actually believe that; you only think you do. In actual fact you and I agree completely, let me show you." I assume the ideal end to persuasion is for you both to laugh about it together, wondering how you could ever have been so foolish as to think there was a disagreement. What usually happens, though, is that neither succeeds in persuading the other, and both go away thinking the other an illogical fool. But who says we can't try?
If you still don't believe me, look at what I'm doing right now, what I've been doing throughout this post: I've been persuading you to understand persuasion as I do, by arguing that you already agree, or, more precisely, that you already act in agreement, but just haven't realised.
So, can I change your mind? No, to be honest, I don't think I can, nor can anyone other than yourself. But that's okay, because 98% of the time, I don't have to; I just have to prove that you already agree with me. Sadly, that's not as easy as it sounds...