If governments are instituted amongst men to secure their happiness, then the most important political question on Earth is what is required for someone to be happy.
Everyone has their own pet interests, but I think it's more interesting to prove the issue from a negative point of view, instead of a positive.
For instance, being a spouse or parent isn't necessary for happiness, because Jesus was neither but he seemed to fare well enough. If Jesus isn't a good example, then just look at all of his disciples. What about Saint Francis of Assisi? No one can question that he lived a fulfilling life and chose his situation by his own volition.
Having a job isn't necessary for happiness, because plenty of women, who never had a paid job, have lived happily enough as wives, mothers, or just members of the larger community.
Vast riches, glory, fame, or great accomplishments aren't necessary to happiness, because many poor farmers felt utterly at peace living off their land in sleepy hamlets.
It turns out that happiness requires very few, though very ephemeral, things. This is wonderful news for politics, because it means that politics can actually deliver to every single citizen all the prerequisites for happiness, aside from a good personality which has more to do with genes.
So let's focus on these few universal things, and ignore all the sidetracks:
Happiness requires security. People who fear for their lives or wonder where their next meal will come from cannot be happy. Franklin Deleanor Roosevelt gave a wonderful speech concerning this, saying people have a few extra rights that should have been included in the Bill of Rights: Freedom from Fear, and Freedom from Want.
Freedom from Fear means governments must not oppress their citizenry with arbitrary arrests or taxes or purges, but they must also create a crime-free environment and protect against foreign terrorists or conquerors. Otherwise, no one can be happy, no matter what else is going on in their lives.
Freedom from Want means everyone has their basic needs met, no matter what else happens in their lives. Nothing can go Too wrong. There's a safety net under the trapeze wire. The government must provide for this safety net or it is a failure as a government -- it is a sub-optimal government that provides far less happiness for its citizenry than an alternative, more sharing government could provide. The safety net benefits everyone, even the rich, because everyone runs the risk of losing everything in some mishap or another, but their fear of losing it all is mitigated by the knowledge that the State will take care of them no matter what.
The best safety net is the citizen's dividend. In a rich country like the United States, we could easily provide $12,000 a year to every single citizen of the country, which could pay for all of their basic needs. Food, shelter, clothing, health care, education, electricity, internet, water, everything it takes to just live a normal, healthy, happy, decent life can be covered. The clunky, current system in the United States provides much the same coverage, via social security, medicare, medicaid, food stamps, HUD housing, public education, etc. But it wastes at least half the money it collects for these programs, it doesn't give universal coverage to everyone, and it subsidizes some needs while ignoring other, equally valid needs, that an individual would know best where to spend his money on.
The good news is that the United States, and the majority of the governments of the world, recognize the validity of government's duty to provide freedom from want for its people. The bad news is that corruption and special interests have hijacked this basic public good and funneled it to serve mostly private interests. The New Deal FDR spoke of won't be entirely completed until the citizen's dividend is passed and all the special interests are pushed out of the system and every single person in America gets equal treatment, equal help, equal support under the law.
Even so, a good many Americans feel secure, so the government can be given at least a B on this issue.
The next universal requirement for happiness is affirmation. A person needs to feel that his life has a positive value, and that belief needs to be reinforced by his community. If someone is treated like dirt their whole lives, it is impossible for them to be happy. Not because sticks and stones have broken their bones, but because the ill treatment, the complete negation of their value philosophically, eats away at their spirit. Eventually they come to believe in their own worthlessness themselves, and the work of hatred is complete.
One of the best ways a community can affirm the value of every citizen is to give every citizen a citizen's dividend. There's nothing that says "I value you and want you to be alive" more than $12,000 in your bank account that can pay for all of your daily needs. This is one huge step to keeping people's chins up. The next step is a culture of respect and love for one another. This culture should be promoted in the churches, schools, and media, and it should extend to everyone in the community, regardless of their age, race, sex, sexual orientation, socioeconomic status, ethnicity, religion, or ideology.
There are many people who simply are net negatives in this world. It's no use pretending they're good and lavishing them with unearned praise. But by then it's too late. The real question is how did these people end up where they are today? What must have happened in their childhood for them to turn out so bad? If these 'lost to mankind' adults had been put in a supportive environment from the start, how many of them could have been saved? Aside from a few genetic psychopaths, my guess is the vast majority.
I hold that a normal person, raised well, will become in truth a net positive existence in this world. As a result, it's easily possible for the government, and the culture, to treat normal people with this level of respect. It doesn't have to be much. Just refraining from insulting people is generally enough. Calling people lazy, stupid, ugly, mean, or any variation of these themes as individuals or as group indictments is completely unnecessary and extraordinarily harmful.
Insults do not change people's behavior, they just make people turtle up and bristle like an injured porcupine. They will learn to hate themselves, which is the intended design of these insults, but they will also learn to hate their accusers, which is certainly not the intended design. They will never 'learn' from these callous sideswipes and seek to improve themselves accordingly to no longer merit these insults. They feel that they'll be insulted no matter what they do, so there's no point changing, and they don't have any way to change in the first place, because no one is offering them any help or reward for doing so anyway.
Gentle persuasion and praise of their good points would serve infinitely more in this regard, and give them an incentive to care about the well-being of the people around them as well. Respectfully listening to people when they talk to you, giving them right-of-way in traffic lanes, and smiling when you cross paths, are also very simple things that end up having a huge cumulative effect.
Affirmation from within is equally important to affirmation from without. To be happy, people need to keep their minds engaged and feel they are good at something. They need to feel that what they are doing is worthwhile, and has some greater meaning or purpose behind it. Religion or philosophy is necessary for happiness. Therefore, people need to be given a thorough education, such that they can reason abstractly about these matters, and such that they have a strong grounding in the moral virtues. Happiness cannot be found at the bottom of a cup or the tip of a needle. It must stem from the sacred and the divine. There are many, many paths to God, but there are no paths that lead anywhere else. They're all dead ends.
Thankfully, in the modern era, even people of mediocre stats have access to a vast array of sports, games, and other such events they can thrive in, and most of them are multiplayer. This gives everyone the taste of 'friendship, hard work, victory' that is so necessary to a happy life. In addition, even if someone can't amount to anything, if they love something dearly, they can take a vicarious pleasure in any one else doing it. This multiplies our opportunities for happiness a million-fold.
Suppose you like gymnastics, so you take a couple years of lessons and learn many basic things about the sport. You don't have the talent, or perhaps the perseverance, to continue trying to improve to the very heights of the sport. But you do develop a sense of camaraderie and appreciation for the gymnasts who do go on. In that case, the Summer Olympics could be one of the happiest times in your life, just by watching what your compatriots do on the stage of your dreams.
It is not true that spectator sports, reading novels, watching movies or television, or the like are worthless or soulless. So long as people have fallen in love with what they're reading or watching, so long as their identities are all mixed in with the characters who are moving about and accomplishing things, the gentle radiance of these 'heroes' reaches the hearts of everyone involved. Entertainment is the real deal. Entertainment is a wonderful path to happiness, and a lot wider than being 'the best' at something, which, after all, can only support a population of one.
The final leg of the tripod of happiness is 'progress.' Or in other words, hope. People can endure a lot, if they feel it will get better in the future. People can even resign themselves to death or torment, if they feel that in the future these tragedies will no longer occur to other people they care about.
Religion has been good at giving people hope for a long time, but its claims about an afterlife are rather dubious. This is why it's so important to provide a new source of hope in people's lives. Sick people don't just have to pray for a cure, they can hope for a scientific breakthrough, like the one that shows Alzheimer's can be reversed in mice that came out a few days ago. The world needs, today, a continuously improving material situation, not just ephemeral, unproven promises from old books.
It is therefore a necessity for the government to do whatever is necessary for the sake of continued economic growth, scientific innovation, and artistic embellishments. People need to feel that tomorrow won't just be a repeat of today, but something much brighter. This gives people the will to go on living, and the wish to bring children into the world, which is necessary for a healthy community.
Mindless novelty, even the illusion of change, is a good thing. It's better when another superhero movie comes out, just like all the previous ones, than a literal rerun of the previous one. Humans are easily satisfied creatures. But it would be even better for people if they could be excited about real breakthroughs that were both promised, and then delivered, by their governments.
Remember the World Fairs of the 1800's? The Crystal Palace, the Eiffel Tower, and the Space Needle in Seattle, were all results of the World Fair. The people of the 1800's loved these events. They were thrilling, the events of a lifetime for the people involved. Talking and showing off, literally, about all the great things that were now possible due to scientific advancements shouldn't be reserved for the dusty corners of technical journals. These advances need to be popularized and celebrated for all to see, so that progress is a real visible occurrence in their lives. What happened to the beautiful cathedrals towns used to make as a celebration of their city's progress? We need more of the old Roman spirit that, after winning a war, built some enormous temple to a random deity as thanks, and then invited everyone in to come and gawk at it.
The International Space Station is a good example of this sort of spirit. So is the Large Hadron Collider, and the Hubble Telescope. But we need more! It's high time we put a man on Mars. It doesn't matter if it's just a ridiculous waste of money. What matters is the principle of the thing -- never before has mankind ventured to another planet, but now it has. That's the sort of visible progress which gives people hope about the future. Hope is more precious than any present reality. If we bankrupt ourselves to put a man on Mars -- then it was worth it. People can suffer almost anything so long as they see reasons for hope about the future. Meanwhile, if they know that the situation is hopeless, they won't endure even a paper-cut in the present. They will forsake all burdens and just crumple into a lethargic heap. What's the point in continuing when hope is gone?
Milestones of progress can energize people back into giving their best, and giving their all, throughout their lives. Government should put a hefty priority on creating these milestones, because they aren't just good in themselves, they're also good as a symbol for people's personal lives, that they should continue striving for the future too.
If people feel secure, affirmed, and hopeful, they will be happy. If they lack any of these three things, they'll be unhappy. The government has the means, on average, to provide all three of these human goods to the people, and therefore it should. The greatest good for the greatest number demands it. Any citizen who doesn't demand it from his or her government would be a fool not to. There's no point accepting a sub-par life when a good one is just around the corner, ready to grab.
It doesn't take much to be happy, a lot of things can be cast off and given over to personal tastes, but if something is necessary for happiness, that means it's universal. Universal goods are public goods, subject to the public domain. If we're ever going to be a happy world, government needs to get back into the game.