Kanrry asked:

Why do we exist? What is our purpose? What happens after death?

Answer by Massimo Pigliucci

Those are three fundamental questions about human existence that have probably vexed us ever since we have been able to pose questions to ourselves. Arguably, they represent the very reason for the existence and persistence of religions, and they have kept philosophers busy for millennia.

The answers I am going to suggest avoid altogether any religious reference or transcendental approach, for the simple reason that I don’t think there is any evidence for the existence of the transcendent (which in this context can simply be understood as the supernatural), and therefore no reason to seriously entertain the notion. On this I am with David Hume, who in An Enquiry Concerning Human Understanding (1748) said that ‘In our reasonings concerning matter of fact, there are all imaginable degrees of assurance, from the highest certainty to the lowest species of moral evidence. A wise man, therefore, proportions his belief to the evidence.’

If not from mystical traditions, however, when do we get at the least tentative answers to these existential questions? From philosophical reflection on the body of available scientific findings. Indeed, the above are precisely the sort of questions that show how a combination of science and philosophy — what I often refer to as ‘scientia’ (knowledge in the broadest sense) — is the most powerful source for understanding the world that we have devised so far.

In order of appearance, then: i) Why do we exist? As best as we can tell, we do not exist for a reason, i.e., human existence (or, for that matter, existence in general) does not have what Aristotle would have called an ultimate cause. It has only material causes, the sort of causes that are better understood as answering ‘how’ rather than ‘why’ questions. We exist because we are one of millions of different products of billions of years of biological evolution that took place on what is likely one of billions of planets in the universe. There is no reason to think that our eventual appearance in the history of the cosmos was preordained or inevitable. It just happened, and it may very easily not have. This is not to say that our existence isn’t special, in the sense of likely being a rare, if not unique, outcome of evolutionary processes. We do not know how many other intelligent species there are in the universe, but it is possible that that number isn’t very high — given how many conditions have to be in place for the emergence of life, not to mention of the kind of intelligent life capable of language, culture, and technology. And it is all but certain that we are the only intelligent beings of our kind in the cosmos, meaning that our particular biological type presumably evolved only here on earth. So, we are special, in a way, probably even unique, but not for any particular reason other than a long string of chance events.

ii) What is our purpose? That depends on the level at which the question is asked. If by that we mean whether there is a cosmic, universal purpose behind our existence, then the answer is no, as implied by the answer to the first question above: since no plan went into evolving the species Homo sapiens, let alone into producing any particular individual belonging to our species, then obviously it makes no sense to talk of a cosmic meaning of our existence. However, of course we as individual sentient beings are perfectly capable of attributing meaning to our own life. For most of us that meaning comes from a combination of having loving relationships and being able to pursue our own goals and interests. The ancient Greeks talked about eudaimonia, a life of flourishing, which consisted of leading a morally virtuous life, striving to excel at whatever it is that interests us, and cultivating friendships and family relations. By and large, that ancient concept is confirmed by modern social science, which has uncovered the presence of those very elements as sources of our happiness, and their lack as sources of our unhappiness.

iii) What happens after death? Nothing. As Epicurus argued, there is no reason to fear death because ‘death, … the most awful of evils, is nothing to us, seeing that, when we are, death is not come, and, when death is come, we are not.’ Less poetically, everything we know from modern science tells us that our consciousness, and with it our sense of self, cease to exist the moment in which our brain stops functioning. Our bodies keep going for a while (indeed, they may even be maintained artificially ‘alive’ for relatively long periods of time), but eventually succumb to decay. Over a relatively brief period of time the complex biomolecules (proteins, DNA) that made our life possible disintegrate, and the simpler molecules of which they are composed re-enter the cycle of elements in the geo-biosphere, possibly to be reassembled in part into other living organisms, be they plants, animals or bacteria. In no sense, however, does this recycling amount to anything like the sort of reincarnation of which a number of religious and mystical traditions speak. Should this fate worry us? Not according to Epicurus, and I see no reason to disagree with him, on either scientific or philosophical grounds.