 So, I think the history of happiness helps us understand why happiness is such a wide term, because essentially it is a more than 2,000 year development of a concept that have been back and forth over three questions, first, what is happiness, secondly, when are we happy, and thirdly, who decides whether we are happy or not. So if we take the what is happiness, well that is essentially a battle between two broad perceptions of happiness. On the one side you have Aristotle, who says that 2,000 years ago, happiness is purpose. Happiness is what's doing right for humankind and society. On the other side you have happiness is pleasure. So Epicurus, essentially the Hugh Hefner of the antique, believed that maximising pleasure and minimising pain, that is what happiness is. I think after 2,000 years we've certainly merged the two, and people might be hedonists or have the same perception of Aristotle, but I think for the majority of us happiness is something in between. So it's not abstaining and it's not having massive orgies, it's just having really good sex with your wife. So perhaps that's where they meet. So that's perhaps where what is happiness has evolved from and to. In terms of when are we happy, the history there is a development over are we happy in this life or in a potential afterlife. So if you take Christianity, there was a dual conception of happiness. They ended up admitting because work from Aristotle came back into Europe during the Renaissance and Aristotle talked about happiness in this life. So the church had to acknowledge that there was happiness in this life, whereas earlier that said that happiness was only reserved to paradise in the afterlife. So they started to work with a dual conception of happiness that said yes, there is happiness in this life, but if we sort of go through a lot of hardship, a lot of trouble, if we sacrifice ourselves, then we'll experience the real happiness in the afterlife. So that is also the development that we've seen over time. Can we be happy in this life or is it something that is reserved for the afterlife? So when are we happy? And then thirdly, who decides whether we are happy or not? The antique, it was up to the gods to decide who would be happy and it was reserved for the few. One of the good things that did happen with Christianity for example, was a sort of a democratization of happiness that suddenly everybody could become happy. Everybody could achieve happiness in the afterlife. And during the Enlightenment, happiness also became something that governments and we ourselves were in charge of. In the Declaration of Independence, we can see that in the sort of highlight of the Enlightenment that it's written into a grand manifest that yes, we have the life or we have the right to the pursuit of life, liberty and the pursuit of happiness. And that shows where we have gone from happiness was something that the gods decided who could achieve to something that we were in charge over. And that is where we are today.