1. Animals like elephants, chimps, dolphins, magpies etc. are known to pass the 'mirror test'.
2. If you draw a spot on their foreheads and put them in front of a mirror they'll try to rub it off.
3. So scientists have recognised that they're self-aware, just as children are as early as 18 months.
4. So animals and children share a sense of basic self, recognising what's happening in the moment.
5. Cognitive scientists call this reflection 'episodic memory': the memory of undergoing experiences.
6. There's another kind of reflection that develops a little later in humans, and perhaps never in animals.
7. Cognitive scientists call this 'autobiographical memory': the memory of linking present with past experiences.
8. Like humans can not only imagine what happened before, but imagine by putting their current self in the past.
9. So whenever they access their autobiographical memory, they can put themselves into a mental time machine.
10. The issue with having an autobiographical memory is that it keeps supplying life episodes to fashionise our self.
11. Which means it's up to each of us to create and construct our life story with an assorted choice of life episodes.
12. So the mission of every rational individual is to build out a self, which philosophers call the constitution of self.
13. And philosophical observations on what it means to live well lead people to two goals: meaning and happiness.
14. At the same time, psychological evidence concludes that aspects of meaning and happiness can be in conflict.
15. Like activities increasing meaning can reduce happiness; activities increasing happiness can reduce meaning.
16. For instance, raising children has shown to reduce happiness, but people do so because it gives them meaning.
17. So happiness and meaning are two distinct aspects that stretch our lives, although neither dominates the other.
18. Meaning and happiness-filled episodes are created and supplied into our autobiographical memory to create life.
19. Or life story, which we're burdened to constitute/build, that clarifies the maxim: to live well is to live narratively.
20. If Nietzsche wrote, 'We want to be poets of our lives,' the neurologist Oliver Sacks concurs, we live in narratives.
21. There are two fundamental life narratives, as articulated by the philosopher Jim Holt: 'Nietzschean' or 'Platonist'.
22. The Nietzschean way is to make life as one wills, of individuality or originality; one that's organised on newness.
23. The Platonist way is to make life not on newness, but on goodness; one that's organised on some objective value.
24. The Nietzschean way relates to happy, episodic types who have no interest in the past, except it forms their now.
25. The Platonist way relates to meaningful, autobiographical types who seek worthwhile projects for societal good.
26. Both have their arguments; one prioritises happiness, other meaningfulness; one is ephemeral, other is enduring.
27. But the truth remains, that the poetry of our lives is orchestrated by two narratives whether we realise it or not.