People like to think, when they have a choice to make, that every possibility is open to them, that they are really free in some way to choose whichever they like. Even putting aside the physical nature of the brain it is pretty clear this isn’t the case, simply from a psychological point of view. People always pick the choice that seems best to them and so, all other considerations aside, we are thus on a set of tracks from one choice to the next from one apparently best option to the next. Now, obviously, determining what will seem best to a particular person isn’t always easy, and often we will be unable to predict what will seem best even to ourselves at the time we will have to make the choice. Because of this unpredictability we have the illusion of “freedom” of the kind where we could really pick any option, but it is only an illusion, although we still have the real freedom of self-determination. (And, before some tries to disprove this claim by intentionally picking a less-than-optimal choice, let me point out that clearly if you pick the less optimal choice then you think that disproving this claim by doing so makes the less-than-optimal choice worth it. But then that choice really does seem best to you at the moment, even if it is sub-optimal by the standards you usually judge choices, which don’t take into account philosophical worries.)
Because people make choices in this fixed way we are open to purposeful manipulation by others. To manipulate someone, let us agree to say, is to affect someone so that they make a different choice than the one they would have made without manipulation. In this sense of the word one obvious way to manipulate someone is to take away all but one of their options, thus forcing them to take it. For example, if someone was in a maze and they found themselves at a junction we could manipulate them into following one of the paths in this way by lowing walls that block the other options. This is, perhaps, the least interesting way to manipulate someone. More cunning is to affect the choice someone makes by affecting which option seems best to them. And one way to do that is to diminish the value of the option that is currently perceived as best, perhaps by threats. To return to the example of the maze, to manipulate someone in this way would be to affect their perception of the other paths besides the one we want them to go down to make them seem less desirable. Putting up signs saying that the other paths contain landmines would probably do the trick, whether or not we actually can find some. The inverse of this is also possible of course, instead of lowing the perceived value of the options other than the one we desire someone to pick we might instead raise the value of desired option, perhaps with bribes. Returning to the maze, for one last time, this kind of manipulation might be effected by leaving a trail of money along the path we desire the person to take, or possibly signs saying that there is food to be had along it if they have been trapped in our thought experiment long enough.
Given that the choices we make play a central role in ethics and that manipulation affects how we make choices we might suspect that manipulation might have an effect on the ethics of the situation, both for the manipulator and the person being manipulated. But, at least for the person, being manipulated, the ethical consequences of their choices aren’t affected, contrary to what some might intuitively think. Whether a choice is good or bad depends solely on the intended consequences of that choice by the person making it, it doesn’t depend on how they were led to make it one way or the other. If that doesn’t seem plausible simply consider how someone might try to excuse their bad choices given the description of manipulation given above. Could they legitimately defend their bad choice by claiming that it seemed best for them at the time? I think not, because if they could every unethical behavior could be excused; clearly when people act unethically they do so because they think it is the best choice they can make at the time. They think that by acting unethically they will receive some advantage, that things will turn out better for them if they do so. And the person manipulated into acting unethically is in exactly the same position in this respect with the person who chose to act unethically without manipulation, they acted unethically because they thought that things would turn out better for them if they did so, whether because of some bribe or some threat. On the other hand, whether someone was manipulated into acting unethically does affect how that choice reflects on our view of them as a good person (or a bad person), because we make such judgments based on how much value the person places on acting ethically; on how likely they are to act ethically in any given situation. Thus if the person acted unethically only because of some huge threat or bribe this would be consistent with them being a good person, because even a good person can act unethically.
This brings us to the other half of the question, namely whether it is wrong to manipulate people. Some may again lean towards the intuitive idea that manipulation is intrinsically wrong, possibly because manipulation is a word with negative connotations. Still, I would deny that anything is intrinsically wrong. It seems clear to me that whether manipulation is good or bad must be decided on a case-by-case basis as a result of the effects it has. But this doesn’t prevent us from making some broad generalizations. Generally then manipulating people by threatening them or by blocking them from making other choices will be an unethical thing to do because you are making them worse off by doing so (as things were they could have picked some excellent choice, but your manipulations blocked them from picking it and now they must settle for less). But, naturally, this can be outweighed if the other consequences of their new choice are sufficiently beneficial. Maybe they are an intrinsically selfish person and by threatening them we force them to make an ethical choice in a situation where it has large-scale consequences. Thus, overall, our threatening them would still be the ethical thing to do. Conversely then manipulating someone by bribing them would seem like a good thing to do, because it makes one of their choices even better than the choice which was previously best. And, just as threatening people could be good if it led them to make an ethical choice, so can bribing people be bad if it leads them to make an unethical choice.
Of course this discussion has so far presumed that people are accurate assessors of the choices before them, such that what they perceive as best is actually best. But in many cases this is not so, the best choice may be hidden from them and they may only be picking a choice that is somewhat good. Thus our manipulation could very well be an alteration of appearances simply so that the best choice really does seem best. For example, by informing someone about all the facts we may manipulate them by changing which choice seems best, but we haven’t affected the actual consequences of their choices at all, nor are we pretending to. If we consider whether this counts as threatening or a bribe we see that it depends on whether the person was previously overvaluing some choice, in which case it counts as threatening, or undervaluing some choice, in which case it counts as a bribe. But, obviously, more accurate information is always good for a person. Thus what was said previously about threatening and bribing was really a loose way of describing manipulation capturing only those cases where appearance agrees with reality. What we had to say about threatening really applies to any case in which we cause someone to choose an option that was worse than the one they would have picked without our interference, and what we said about bribery applies to any case where we cause someone to choose an option that is better than the one they would have picked otherwise. Under this more accurate way of looking at matters giving someone more information about their options always falls under the category of bribery and is thus always a good thing, unless the choice they will make is unethical, as described above.
But, despite all this, some may still feel that manipulation is in some way unethical or wrong, that it diminishes people’s natural freedom to choose, and thus must be avoided out of a matter of principle. Well, I have bad news for those people: the manipulation of others is essentially unavoidable. If you have any affect on the world at all then there is a good chance that, on occasion, you will affect the choices people make, and thus will be manipulating them. For example, let us suppose that you write a blog entry, as I have today. By making it available for people to read I have affected the options available to them when choosing how to spend their time. And, if they read it, I have effectively manipulated them into doing so, although without any specific intention to have that particular effect on that particular individual. Because of this it seems hard to condemn intentional manipulation as a matter of general principle given that it not necessarily any more or less harmful than the unintentional manipulation that occurs constantly.