You're certainly correct that there is a tendency in suppose that reason and emotion are antagonists, and that with respect to morality in particular, we should be guided by reason rather than emotion. And there may be major figures in the history of philosophy (Plato comes to mind) who really did see reason and emotion as in stark and irreconcilable tension. On this view, reason and emotion are essential partners in moral thought and deliberation instead of implacable antagonists.
However, there's a pretty significant segment of philosophers, both historical and contemporary, who don't think that reason and emotion are such enemies when it comes to moral reasoning and decision. A popular view (one that I myself find attractive) distinguishes between moral truth and moral knowledge: Emotions, on this view, are not a source of moral truth, but do enable you to know moral truths.
Suppose that, as you end a day of busy holiday shopping, you see a fellow shopper carrying a large bundle of shopping bags. She slips and falls on a patch of ice, evidently injuring herself. Feeling dismay, alarm, and sympathy -- what we might call morally salient emotions -- you offer help to the fallen shopper. Let us suppose that it is true that
It is morally right for you to help the fallen shopper.
In this case, your emotions helped you discern this truth. Without the ability to feel dismay, alarm, or sympathy, you would not have known that this is what it was morally right for you to do. However, it is not the case that it is morally right to you to help the fallen shopper because you felt dismay, alarm, or sympathy. It is morally right to help her because she needs aid, is in pain, it would be generous, and so forth. So on this view, your emotions help you to discern moral truths, but are not the source of that truth. Emotions are aids to moral reasoning, but are not what moral reasoning is about.
This position is attractive because it seems to reconcile two plausible claims. On the one hand, a person who lacks the right kind of emotional sensitivity is unlikely to appreciate what her moral obligations are and unlike to act reliably in morally praiseworthy ways. A person who (for instance) lacks all sympathy, respect, care, and so on, ends up morally deaf, cognitively cordoned off from moral realities. (At its worst, such a person exhibits psychopathy.) At the same time, emotions are imperfect signals of moral truth. Sometimes a person is sympathetic with, or cares for, someone who doesn't morally deserve sympathy or care. In other words, from a moral perspective, our emotional reactions need to be shaped or cultivated in the right way -- and the 'right way' is in accordance with reason.
Most philosophers, me included, would say that we do not choose to feel what we do. Ever since the ancient Greeks, emotions have been thought of as 'passions', because we are passive, not active, in experiencing emotions. We 'suffer' or 'undergo' them, rather than bring them about. It may be that we can make choices, e.g. about what kind of person to be, that will change our character and that will result in our having different emotions in the future. For example, we may choose to face our fears, to become more courageous, and then feel less or fewer fears in the future. But we cannot choose what to feel in the present. Or again, we may have some indirect control over what we feel, by focusing our attention on certain aspects of a situation rather than others. But we can't directly control, by choice, what we feel.
We do make moral choices as well. Given that we don't choose our emotions, it follows that when someone feels shame, this is not a moral choice they make. Instead, we might say that our moral choices apply to actions and perhaps to future character traits, like generosity or courage. Suppose, then, someone chooses to act in a way that then causes them to feel shame, e.g. perhaps they betray a secret they had promised to keep. They choose to betray the secret, but they didn't choose to feel shame. We can't choose what to feel ashamed of.
Perhaps this looks like a threat to moral autonomy. I don't think so. Perhaps the person thinks that it is not wrong to betray this secret (e.g. it could save someone's life). Then they feel shame, but they think that the shame is inappropriate - they don't think that they did anything wrong even though they feel shame. Our feelings and our moral judgments don't always line up.
This situation strikes me as quite normal, when in adulthood, we reject some of the moral rules of our childhood, e.g. someone who feels guilty at not going to church on a Sunday morning, even though they stopped believing in God years before.
Depends on what you mean, doesn't it? But even after we sort that out, the answer may still be that it depends.
A headache is a feeling but not an emotion—at least, not as most people use the word. Anxiety, at least a good deal of the time, is also a feeling rather than an emotion, but it can go either way. A free-floating, undirected anxiety is a feeling. But it doesn't seem too strange to say that anxiety about something specific counts as an emotion.
So maybe we could say that emotions are feelings with objects. At the end of the day, that won't do. Still, it gets at something. We tend to save the word "emotion" for states that are about something, or have some sort of content other than just raw feels. But that's pretty clearly not enough. That slice of apple-rhubarb pie in front of me may fill me with a very focussed feeling of hunger. But that feeling doesn't count as an emotion. What's missing?
The answer, perhaps surprisingly, is reason. Emotions can be justified and they can respond to reasons. If I'm outraged at someone and someone explains the situation to me, the change in my beliefs may well make my outrage evaporate. Sexual arousal seems different. Suppose there's someone whose voice I just find arousing. Reasons and justifications don't have anything to do with it. Hearing those flowing tone and those liquid vowels just does it for me. My feeling has an object, but it still doesn't seem to be an emotion.
So on balance, the best answer may be "feeling" rather than "emotion." But if you want to think more about it, you might look at this piece on emotions in the Stanford Encyclopedia of Philosophy.
Ethically speaking, I'd say that your present guilt at not having felt guilt in the past speaks positively of your own moral character.
As it turns out, you did not in fact have reason to feel guilt in the past because you had not injured another person. Nevertheless, to feel guilt when you (believe you) have injured another is morally valuable. For one, such guilt indicates a recognition of your own wrongdoing and is evidence of your moral knowledge and perceptiveness. And from a more consequentialist or utilitarian point of view, being susceptible to guilt encourages us not to injure others. After all, guilt feels bad, so being susceptible to guilt is good inasmuch as the desire to avoid justified guilt should engender a desire to avoid injuring others.
The guilt you're feeling now is what philosophers such as Harry Frankfurt call a 'second-order' attitude: Your present guilt is directed at (or we might put it more technically, has as its object) your earlier lack of guilt. It is an attitude toward one of your own earlier attitudes. That may seem odd, but in fact second-order attitudes are very common. We often have, for examples, desires regarding our desires. I might desire mocha brownies, while also desiring that I not desire mocha brownies. They're not healthy for me after all. In fact, your present guilt can be seen in precisely those terms: You feel guilt now because you desire to have had different attitudes in the past. But the fact that you feel guilt now is a sign of moral maturation on your part. Your attitudes toward your own actions and judgments are becoming better aligned over time.
So in short: Don't worry -- feel guilty. At least for a little while!
You should also read, "How Can We Be Moved by the Fate of Anna Karenina?" by Colin Radford, and the literature that developed in response to it.
I see no reason, in principle, why not. If knowledge were not possible without emotion, then no emotionless computer could achieve knowledge, which would come as a shock to the proponents of artificial intelligence (AI). Nor do I see anything in the concept of knowledge itself that rules out knowledge based on reason alone without any emotional content or associations. I don't mean to say that emotion can't play an essential role in some kinds of knowledge, only that I can't see how emotion would be essential to every kind of knowledge.
I doubt that there is a distinction to be made between kitsch and the sentimental. What is wrong with these aesthetic categories is that they are so undemanding. I very much enjoy both, especially the little cute things one can hang from bags, like the small animals and symbols, and also the emotions induced by country music. Both readily produce pleasurable emotions in those conditioned to enjoy them, but they have no depth. Except for irony, there is no way of using them to extend our understanding of what we are seeing or hearing. That is not to say that there is anything wrong with them, it is just that they have a limited use and once that is over, they fail to resonate with us.
There is no good sentimentality. As Kant suggested, if we are to make aesthetic judgments we need to hold our feelings in abeyance.
Suppose that 201 groups of people each set themselves a noble goal. If I were a member of a group that achieved its goal, I might well be proud of my group. If that pride is reasonable (and it might well be) I'd still have the same reason to be proud of my group if other groups—even all of them—achieved their goals too.
As for the point of pride, I might indulge in feelings of pride because it makes me feel good, but that probably gets things the wrong way around. Some things just make us feel proud. Pride makes most sense, perhaps, when what we're proud of is something that we deserve some credit for, but we also sometimes feel proud when someone that we're associated with accomplishes something. Suppose my friend works hard on a book and it wins an award. I might very well feel proud of her, and that doesn't have to mean that I'm trying to take some of the credit for what she accomplished. We might ask what the point is in this feeling of pride, but the question seems beside the point. My friend did well; feeling proud of her seems a natural reaction.
Pride in one's friends might also serve a social function. It might, for example, strengthen bonds between people and help others feel motivated to do well. But feeling appropriately proud of my friend doesn't have to be motivated by any such considerations. Indeed, if I had to gin up my feeling of pride by thinking of the good consequences it might lead to, it's not clear that the word "pride" would really fit.
All this said, national pride is a funny thing. People tend to be proud of their countries, and even if there's nothing inconsistent in members of every nation feeling national pride, consistency isn't enough to give us reasonableness. After all, if it can make sense to be proud of one's country, it can also make sense to be ashamed. And in some cases, shame might be the more reasonable sentiment.
It's an empirical question, but I'd hazard a guess that a country with very low levels of national pride might not be a very successful one. A country whose citizens are proud might also be a country whose citizens are more willing to participate in civic life and to make sacrifices for important goals. If that's true, national pride would serve a larger function than simply making the people who feel proud feel good. But national pride, especially the kind that sees one's country as special or unique, can also be a dangerous thing. Whatever good national pride may sometimes serve, the capacity for thinking hard and critically about what one's country does on one's behalf is surely at least as important.