- Robert Lawrence Kuhn
- Richard, assuming that intention can cause us to do things independent of brain states, which I will assume for the moment, how then do those intentions get caused?
- Richard Swinburne
- Well, much of the time our intentions are caused fairly automatically by our desires and our beliefs. If I believe that something is the best thing to do and I have no contrary desire, I will do it. If I believe – I want something more than anything else and I don't believe it's wrong, then I will do it. But, sometimes we have to make a choice. We have to make a choice between alternate good things when we think they're equally good, or to satisfy desires when we think they are equally desirable, and above all, we have to make a choice between doing the best action and doing what we most want to do, and it's for that that we're morally responsible. It does seem to us that in these circumstances it's up to us. We realize that we have desires and we act on them and we don't find this puzzling that we do what we most want to do most of the time. But when we have a serious moral problem, when we are having to decide shall I tell the truth when I don't want to tell the truth, or but when I think I ought to tell the truth, here we realize it's up to us. And it's a basic epistemological principle that we should believe that things are the way they seem to be in the absence of counter evidence. So, we should believe it really is up to us, unless you've got any reason to suppose it isn't. Now, what would the reason to suppose it isn't consist in? Well, it would consist in having a deterministic mind-brain theory. It would consist in having a very well-established theory that's saying that these brain events cause these intentions; these brain events cause those intentions. But, it wouldn't be quite as simple as that, would it? Because we form our intentions in the light of our beliefs and in the light of working out the consequences of our beliefs, and if we've got a serious moral decision to make, the situation, if we, if our intentions were determined, determined by brain states we'd be rather like this. Some brain state causes some belief and this belief combines with some intention and a certain series of thoughts, which leads us to have this belief, and that, in turn, leads to the formation of intention. So, we'd need, in order to have a justified belief that the resulting intention was predetermined, we would need a well-established theory of how brain states interact with different kinds of mind states and different kinds of mind states interact with other kinds of mind states in order, eventually, to lead to intentions of a certain sort. Now, I don't think you can have such a theory. I don't think you can have such a theory because the only reason you can have a successful deterministic, or semi deterministic, theory of the physical world is because you can establish general laws by repeating experiments. You can establish a law of collision, for example, an elastic collision between a body of this mass and that velocity with a body of that mass and that velocity, will lead to so and so, because it can be formulated in numerical terms. That is to say, mass 1 times velocity 1 plus mass 2 times velocity 2 is, will lead to another mass velocity product of the same value. Momentum is always conserved. And you can have such a law because you can measure mass and you can measure velocity and you can test it for a number of different masses, and you can have these laws in the physical world because you can measure things in the physical world and the kind of quantities you need to measure are fairly small. You just need to measure a mass and charge and a few other of the primary qualities and velocity, and a few others, that is to say, 15 or 20 different kinds of characteristics plus the measured values of those characteristics of all the elements involved in the situation should enable you to yield the prediction. But once you come to the mental life, you come to things which can't be measured because there's only one person has privileged access to them. You can't measure whether a pain is twice as painful as another pain, and yet, what somebody does depends on whether the pain is twice as painful as another pain. And, the beliefs and intentions we have, if they were put into words, would be put into words which express innumerable concepts which cannot be defined by each other, and the way the words are put together would express different kinds of statements which, again, can't be defined by each other, and people have constant of concepts from each other and all of these concepts have no numerical relation to each other. So, the only kinds of laws you could establish for the mind–brain interaction would concern what a particular person with a particular sort of mental life does in a particular situation. But nobody ever has the same brain as each other, and nobody ever has the same mental life as each other, and therefore, you just won't have enough instances. In fact, you won't have more than one instance of this situation and it won't be a kind of situation which is repeated, and therefore, you can't have the evidence that this is a deterministic system. And if you don't have the evidence that this is a deterministic system, it's not reasonable to believe it is, and therefore, you should believe that things are as they initially seem to be, and that is to say, that your intentions are affecting your actions, so there's no reason to believe that you're mistaken in supposing that you are making up your own mind. That is the way it seems to you. You should believe it. In the absence of counterevidence, my argument is that counterevidence couldn't ever be produced.