Where would we be without emotions? Many philosophers throughout history have thought the emotions serve only to cloud our judgments and actions.
It was terrific to have Martha Nussbaum on Philosophy Talk. Martha is one of those philosophers, like Robert Nozick, John Searle, David Lewis and a few others, who seem to produce more interesting philosophy than seems humanly possible, and not just by repeating themselves, but in virtue of a steady stream of original insights.
In the program I was skeptical about Nussbaum's rather cognitive take on the emotions, and I used some such phrase as "primitive caring." Ken mentions this in his blog, and seems not quite sure of what I meant. Well, I'm not quite sure either, but I'll play with the idea here a bit. There are two roots to my inchoate thoughts about this topic, one based on personal experience, the other on rather theoretical considerations. I'll only discuss the former....
I agree with Nussbaum that how we think of future possibilities has a lot to do with our emotions. If I think that X is going to have a root canal, I am filled with sympathy. Well, not filled, but I have some sympathy for X. If I realize that X is me, a whole different set of emotions rise in my breast, or brain, or heart, or wherever emotions are taken to arise these days. Fear, based on anticipation of pain and discomfort, replaces sympathy. The first-personal perspective is crucial. This is true even for emotions that are not self-centered in the ordinary sense. I may make sacrifices for the benefit of some other being, but somewhere in my conception of that other being will be some relation to me: my wife, or my children, or my country, or the world my children and grandchildren are going to live in. I would probably be willing to sacrifice my life to bring about peace and justice in the earth's future; it's my planet, after all. But I doubt I would do so for peace and justice in the future of Mars, and almost certainly not for peace and justice in Vulcan or some other planet outside our own solar system, unless I thought that peace and justice there would prevent, say, a future invasion of Earth.
Still, in thinking about desires it is crucial to distinguish between the objects of the desire and the agent or possessor of the desire. If X desires that Y have a good time, X is the possessor and Y is the object. Even if I desire that I have a good time, we still need to make this distinction. Egoists sometimes confuse the truth that it is only our own desires that motivate us, with the falsehood that we are the objects of all desires that motivate us. It's theoretically possible and for all I know a noble thing to have desires whose objects have only the most attenuated relation to us, and we certainly lots of people have desires about matters that won't have any effect on the succession of experiences they are going to have between birth and death.
Conversely, it seems to me that no relation between possessor and object guarantees that the possessor will care what happens to the object. Even identity. It is theoretically possible, as far as I can see, that I am fully aware that if I don't move I will be run over by a bus, but I just don't care. I don't mean that it is possible that I prefer being run over by the bus to not being run over by the bus; certainly people get themselves into a state where they want something awful to happen to them. I mean not caring one way or the other. The impending events involving me simply do not arouse any passions in me. I don't care. And so I am not motivated to do anything. Whether this ever really happens, I don't know, but experiences of lethargy, depression, and the like seem to approximate to this condition.
I think ultimately what motivates us is sensations and anticipations of sensations. Any organism that is in pain will try to change its situation so it is not in pain. It cares whether or not it is in pain. Pain is a state that is intrinsically motivating, or at least naturally motivating. This is not quite the same as being necessarily motivating; a human can be trained or drugged in various ways so that pain doesn't bother them. But it doesn't require training to be motivated by pain. It's the natural way of things. It's presumably what pain is for, what Mother Nature had in mind by giving us the capacity for pain. As Hume points out, we would have expected a perfect God to come up with something better---maybe a more or less continual semi-erotic pleasure diffusing all of our body, which diminishes when we are injured. If I twist my ankle, and then walk on it, the semi-erotic pleasure based in my ankle disappears and I quickly stop and limp so it comes back. But Mother Nature does it with pain. Mother Nature, as we know, has rather peculiar goals for Her creations: that they stay alive long enough to procreate, so that there will be plenty of things of their own kind for other things to eat, so they can procreate. So pain is a fine device for her to use.
As Nussbaum rightly observes, there is no one to one correlation between emotions, like despair and joy, and the feelings that are a part of having the emotions. Still, there seems to be a collection of emotional-feelings, that are naturally motivating, the sorts of feelings one wishes not to have or wishes to have and continue having, that are involved in a complex way with our emotional life. It seems to me that no judgment, no matter how certain, how first-personal, or how vividly focussed on, can motivate us without being tied to some of these naturally motivating feelings. While there is not a one to one correlation, there are complex patterns.
Now I don't mean to say that Nussbaum's theory can't account for this, and I certainly don't mean to ascribe to her the conflation of self as possessor and self as object that I see in some egoists. But if I had a theory of the emotions, I would put the primitive phenomenon of caring about which future possibilities are actualized, in the sense of having different pleasant and unpleasant feelings, ultimately related to anticipations and memories of naturally motivating pains and pleasures, at the heart of it. But then, maybe its just as well I don't have a theory of the emotions.