Aristotle said, “Happiness depends on ourselves,” and believed that happiness was the ultimate goal of human existence
Rather than viewing happiness as something that you might experience after passing a test, or while out having fun with friends, Aristotle thought happiness was a measure of your entire life, and how well you had lived it.
He thought that happiness was an end goal, not just a momentary feeling.
Aristotle believed that all of the following were important when trying to achieve happiness:
According to Aristotle, the decisions you make are extremely important.
So, he thought that instead of choosing options that give instant gratification, we should try to behave in ways that provide long-term benefits.
Kant said, “Happiness is the satisfaction of all our inclinations”.
Kant also acknowledges the fact that we don’t always know what’s best for us, saying that human beings are not capable of determining with complete certainty, what will make him truly happy
It might sound counter-productive, but Kant believed that the more you tried to be happy, the more unhappy you would be. 
Have you ever tried so hard to enjoy something that you ended up feeling disappointed? Then you’ll understand this theory.
Instead of constantly trying to attain things that we believe will make us happy, Kant says we should focus on acting in the way that we believe is right.
This could involve:
- Doing things to help others.
- Doing things out of a sense of duty.
- Trying to be as rational and moral as possible.
It wouldn’t include:
- Trying to get rich.
- Working towards material possessions.
- Becoming too focused on selfish goals.
- So, the basic message is to stop obsessing over happiness, and to try and be a good person instead.
When we do the right thing, happiness will naturally follow.
Nietzsche said, “What is happiness? The feeling that power increases, that resistance is being overcome.”
Nietzsche believed that happiness was a kind of power that people could exert over the world around them.
This might sound a little sinister, but it could manifest in many innocuous ways.
For example, to be happy, you might want the power to:
- Live in the location you want
- Work at a job you enjoy
- Have relationships with people of your choice
- Spend your time in the way you want
When the power to do these things is taken away, we feel unhappy and attempt to take back control.
This could be by looking for a better job, leaving an unhealthy relationship, or moving to a new geographical location.
Nietzsche believed that happiness was strongly connected to personal agency and the ability to live life the way you wanted to.
Socrate’s believed that many experiences we might describe as pleasurable, like feeling better after a long illness, were not true happiness – only the absence of suffering.
He thought that happiness should not be based on external things, but on how they are used.
- Using money to donate to a good cause.
- Using intelligence to solve problems.
- Using strength for good, and not to manipulate others.
So, it’s not about what you have – it’s about how you use it.