The two questions are separate. Taking the first, what should I do? Taking myself in isolation, there have been two coherent answers to that question: one is "whatever God says", and the other is "Whatever I like".
I prefer the second of those, but it can use some refinement. Doing what I want now could cause me problems in the future; I need to anticipate, and delay gratification to gain more in the long run.
There is a more subtle refinement too: I am not detached from the world; I can change the world, and in the process change myself. It can be easier to manage myself to be satisfied with what is, than to manage the world to satisfy myself. Dispassion is part of the mix as well.
But that's all viewing one person in isolation - an unrealistic approach. Humans are social, and need to form groups to succeed. As well as pursuing my personal goals, I need to gain the cooperation of my neighbours. How to do that is the larger part of what is normally thought of as the sphere of morality.
The most obvious fact is that the answer varies. What will win me cooperation in one society will have me shunned in another; what works in one century (decade, sometimes) fails in the next.
All we can say is that it is necessary for me to conform to the collective expectations of the other people I interact with - to fulfill my designated role in whatever society.
For that to make sense, I have to know what my society is. In theory that's difficult: it's some group of people who interact with me and share expectations of each others' behaviour. In practice, it's usually easier to identify, but not always. I'll come back to that.
As in the individual case, that is not the end of the story. Some societies allow their members to achieve their goals more effectively than others do. Societies change, as individuals do, and they can fail or be replaced. We can say that each person should do what is required of them by their society, and still say that one society is better than another. It might be better in that it is more useful to its members, or it might be better in a different sense in that it is less vulnerable to shocks, more able to grow in reach and strength.
These judgments on societies matter, because, while seeking our own goals and conforming to our place in society, we still may have some power to direct society in a given direction. If we have a vision of a good society, we can aim to change our society for the better.
One practical aside - the aims of improving society and being a good member of it can come into conflict, and attempts to resolve those two competing priorities are often at the centre in dram and history. Froude's Times of Erasmus and Luther contrasts Erasmus's desire to be a good citizen of Christendom with Luther's defiance of his allotted role in the cause of improving Christendom. In this case Froude comes down on the side of Luther, but the question is more important than the answer.
There's an important point missing: We can talk about what makes a society good or bad, and how a member of society can attempt to change it, but ultimately my aim is to advance my own interests, and that might be most effectively done by changing society in a way that is not better either for the society in its own right or for its members generally.
It seems reasonable to say that societies will do better, for themselves and their members, if they somehow prevent this from happening to any significant degree. That's not a theorem - conceivably an arrangement that permits it may bring compensating benefits that outweigh the damage sustained - but they'd better be very substantial benefits.
I'm trying to keep separate two different ways in which a society can be good - it can be good for its members, or it can be good for itself, seen as a metaphorical organism: able to survive, adapt and improve. Inasmuch as a society is a way for its members to better their own lot, the first good is primary, and the second only significant in that it supports the first.
There are a few different forms that can exist to prevent a society being wrecked by selfish interests. (Again, there are two quite distinct ways of being wrecked: the society can be weakened to the degree that it is replaced, either from without or within, by a different society, or else it can remain secure, but provide less value to its members). The first defence is rigidity. If the society is very resistant to any change at all, then it is resistant to wrecking. The problem is it is unable to develop, and unable to react to changing circumstances. Some societies in the past have been successful for their members by being stable, but the rapid changes in the world and in the capabilities of people over the past few centuries have swept all of them away.
To safely accomodate flexibility, a society must preferentially encourage its members to change it in ways that benefit the society and its members.
There is a three-way trade-off: my interests, the interests of my neighbours, and the interests of the organism of society. We rely on society to allow the first trade-off, between each other, to be resolved in an efficient and non-destructive way. The second tradeoff, between a society and its members, is more difficult.
Nothing I've written here is new. Never mind Carlyle and Froude, quite a lot of it can be found in Aristotle. However, it's not a set of ideas that I've put together before, and includes things that I explicitly rejected when I was young and arrogant.
Also, it's not a set of ideas that provides easy answers to difficult questions. That's always a good sanity check
I promised to write about patriotism, and now I have set up the scenery. Froude's comment
The problem that society solves is how to cooperate with my neighbours; how to achieve more together than we could in conflict, or even more than we could independently. We cannot do this without some framework that enables us to match expectations, and that framework needs to be stable enough for us to move with confidence from one interaction to the next.
The framework can be changed, for the better or the worse. As well as enabling our cooperation, therefore, it needs to be such that I can be assured of continuing to benefit from it in future. The future, though, is uncertain, and it his hard for me to know that circumstances will not arise where my neighbour can gain by destroying the assurances that I have relied on. This is the second tradeoff above, between the members of the society and the society itself. The society exists for its members, but we need to maintain it too.
There is a smaller-scale, easier parallel to this situation, which I wrote about before. When two people become a family, each is threatened by the possibility that the other will destroy or abandon what has been created. Reassurance is at hand, however, through the irrational attachments that people in that position have been bred to form towards each other, which discourages them from breaking the bonds even if it becomes objectively convenient for them to do so. The irrationality is an advantage to the individual, as it enables him to make somewhat binding commitments in the absence of any external enforcement mechanism, and thereby reach more advantageous social arrangements.
My neighbours' love of our country is what enables me to tolerate their freedom, as my wife's love is what enables me to tolerate hers.
It is a threat to the tradeoffs if the society can be changed by individuals who are not dependent on it either practically or emotionally. That is why it is important to know who is in and who is out. This is often looked on as some kind of prehistoric handicap, but it is not. I've been talking about "societies", not countries, so I have not yet closed the loop to say anything about patriotism. I admitted above that we need to identify which individuals are the ones we care about, from the point of view of succeeding personally by fulfilling our expected role in society. There are two answers, on two levels. First, those who we expect to interact with in future. Second, those who can change the expectations that we have towards the first group, and that the first group has towards us. If someone will be dealing socially with me, I need him to be within the social framework. If someone can affect the social framework itself, I want him to be constrained not to damage its effectiveness or longevity.
That's still, on the face of it, rather imprecise. However, for most people, through most of history, it's been very easy to work out. There's a good reason for that: if you don't know who is in your society and who isn't, you are in a lot of trouble - at least your society is, and that means that, in the long run, you are too. With personal love comes jealousy, and with the patriotism that gives a society its longevity comes a certain chauvinism. That's a necessary feature, not a bug. If someone isn't a member of your society, they need to be kept away from it, or at least made powerless over it, lest they damage it.
Tribes work as societies on that basis. We had nation-states for a few centuries, and they worked too, more or less. Now we do not have a society where it is clear who is in and who is out, and where the members are bound to preserve and improve it. We have many compensations, and I haven't proved we're worse off in net, but I've at least shown how we could be, how, other things being equal, patriotism is a virtue.
In the end, we may go back to tribes, or as John Robb has it, to some new kind of tribe.
1 "My own conviction with respect to all great social and religious convulsions is the extremely commonplace one that much is to be said on both sides" - Froude, The Influence of the Reformation on the Scottish Character
2 "I once asked a distinguished philosopher what he thought of patriotism. He said he thought it was a compound of vanity and superstition; a bad kind of prejudice, which would die out with the growth of reason. My friend believed in the progress of humanity--he could not narrow his sympathies to so small a thing as his own country. I could but say to myself, 'Thank God, then, we are not yet a nation of philosophers.'
"A man who takes up with philosophy like that, may write fine books, and review articles and such like, but at the bottom of him he is a poor caitiff, and there is no more to be said about him." - Froude, Times of Erasmus and Luther