It’s a word that we use a lot but is rather elusive when it comes to defining or explaining exactly what happiness is.

The elusive nature of happiness isn’t necessarily because we can’t put terminology on it but because it is relative to the person experiencing it.

If 10 people all go through the exact same set of circumstances, they will all experience varying levels of happiness (or pain) from that set of circumstances.

This is why in research studies, happiness is often referred to as “subjective well-being.”

Happiness comes from the Greek word “eudaimonia.” We usually translate “eEudaimonia” to mean happiness or welfare. However, a more accurate definition is “human flourishing.”

The Greek philosopher Plato describes it to be “the good composed of all goods; an ability which suffices for living well; perfection in respect of virtue; resources sufficient for a living creature.”

Simply put, eudaimonia is having your needs met and living well in a way that is also virtuous.

In Nichomachean Ethics, Aristotle, another well-known Greek philsophers, says Eudaimonia means living well and doing well. It’s gained by proper development of your capabilities and pursuit of excellence and virtue through reason.

Great, now that we have all of our Greek philosophy of happiness out of the way, let’s jump back into the 21st century.

According to the great Shawn Achor, happiness is the joy we feel striving after our potential. It implies a positive mood in the present and a positive outlook for the future.

Now to be in a positive mood means that you have to have positive emotions – which is he defines as “pleasure combined with deer feelings of meaning and purpose.”

The 10 most common positive emotions? Joy. Gratitude. Serenity. Interest. Hope. Pride. Amusement. Inspiration. Awe. Love.

All this philosophy is great, but how do we actually “measure” happiness – or subjective well-being – or whatever you want to call it?

Achor proposes there are 3 measureable components of happiness: pleasure, engagement, and meaning.

So how do we take all this information and synthesize it briefly?

Happiness is the state of human flourishing. It means we are living and doing well. We experience pleasure through having our needs met and experiencing positive emotions. We engage with the world around us in a way that we have positive experiences and feel meaning and purpose.

Note: this is part of a series on happiness. For Part 1, click here.