Edit March 19, 2023: The appendix of a new post defines the backwards MoL more clearly.
You're a few beers in and someone at the table sputters out the big question: "so, what's, like, the meaning of life?". And the downward spiral begins ...
Before we get to the meaning of life, let's discuss the idea of an untruth. The idea of an untruth is simply that it's a fact that's neither fully correct nor wrong. It’s not as truthful as a truth, not as wrong as a lie.
We often use untruths to convince ourselves of dubious things. Who hasn’t said to themselves that it's fine to drink the occasional coke, even as their inner nutrition expert screams in agony? For most people that aren’t in a serious medical condition, it’s simultaneously true that drinking a coke won’t hurt you, and that ideally one should never drink coke. That it’s ok to drink coke as part of a balanced diet is a grey-zone statement, and the reason why there isn’t one simple truth is because of the vagueness of the word "ok".
We also use untruths in whether to settle or to pursue more. Take the common mindset of "I like exactly who I am, and there's no need to change myself". While self-acceptance is great, if you take it literally, this implies something like "I am the best possible me that I am, and even if I mustered up the courage to finally pursue my lifelong dreams of joining the navy seals and doing a PhD in philosophy I couldn't be happier."
That doesn't sound too realistic, but this act of self-affirmation is a useful untruth. While things aren't as good as they could possibly be, I'd wager that most people are happier subscribing to the saying than not. Not to mention that if everyone got a philosophy doctorate, the world would break! So among the untruths that one could tell themself, this one is a good choice for self-acceptance.
In my favourite podcast, the host often ends by asking the guest what their meaning of life is, and typically the guests are caught left-handed. Keen to flabbergast, I started asking around me, and indeed found the question usually catches people off guard.
An issue is that there are many different frames from which one can answer this question. The meaning of our lives to the human species is that we make children. To capitalist society, it's to consume and produce. To ourselves, it’s often experiencing happiness and love.
There are so many plausible meanings that one can assign their life that any claim to the one meaning is probably an untruth. This has two implications. First, to acknowledge the meaning of life to be an untruth is to recognize that there are multiple plausible answers, and that it’s even possible to simultaneously accept multiple. Second, just as some untruths lead to better outcomes than others, there are better and worse ways to choose your meaning.
Before moving forwards, I recognize that calling one’s own meaning of life an untruth sounds pessimistic; this sounds like saying that meaning is nothing but a lie. My take on this is that we should dissociate the definition of an untruth from that of a lie, and see it rather as choice. There is no one meaning of life that we're born into. As we discover ourselves, we have the agency to choose what we mean to ourselves, and with it, the story of how we've lived so far, and the road that we will go down.
I'm sure that there are many strong ways that people can choose their meaning, but regardless of how they do so, I propose that the meaning (or rather, the set of meanings) they end up with should fulfil two roles:
These requirements imply two simple definitions of one's meaning of life (MoL). (MoL will refer to meaning of life or meanings of life depending on the context)
One chooses a forward meaning of life to guide them to live their days in satisfaction and fulfilment. One consults their forward meaning when making major life decisions, and might periodically reflect to make sure that they're still in line with it. A common forward meaning is to leave your mark on society, and I see "alleviating suffering" as a forward meaning as well.
A simple forward meaning of life isn't the same as a simple life! I view "being present" as a compelling forward MoL. I'm the most present when I'm with people, so the first step would be to build a family and a network of friends that I care about. And yet, my burning desire for productivity locks me into my head unless it's fulfilled. For me, that looks like applying for PhD programs and working in the evenings. And of course, I can't plunge myself into the intricacies of a conversation if I'm worrying about whether I'll make next month's rent, so I need to secure some form of basic income. And so the simple policy of being present results in a complicated balancing act between the major aspects of life.
One chooses a backward meaning of life to find purpose in what they have done. When things aren't going well in life (and also when things are!) this question justifies what it's all been for. I presume this is also an inevitable question to those who have retired from their jobs. To reflect on your backward meaning, a thought experiment would be the things you're proud of having done, if this were your last day on Earth.
I believe that the backward meaning of life can be very different from the forward one. For example, say that Bobby the engineer works 12 hours a day building drones in Shenzhen because his forward meaning is to change the world. It’s all going great until he gets diagnosed with a lethal cancer. Building drones may have filled Bobby’s days with satisfaction and fulfilment going forwards, but looking back on his life, maybe the robots won’t be what Bobby’s going to remember.
On the other hand, one can get burned for confusing their backward MoL for their forward one. As a toy example, say that Alice did the "last day on earth" experiment at the end of high school and decided that both her backward and forward MoL would be reading books. A decade later, she's a librarian for 40 hours a week and she works an additional 10 hours a week to send her children to school. Busy with life, Alice goes days without reading. A better forward MoL chosen by the 18 year-old Alice could have made her into a classical literature researcher, where it's part of her job to read! Counter-intuitively, one can do a better job pursuing their backward MoL by pursuing a different forward MoL.
In light of this theory, let's discuss some of the ways that people have told me they derive meaning.
Happiness: This and similar responses like "to experience the world" and "to feel fulfilled" are probably what I've heard the most. It's by no means a simple-minded answer, given that thinkers like Aristotle came to it as well. Among the untruths that answer the MoL question, happiness sounds particularly correct - maybe even self-evident. However, I don't think that this alone is a useful backward or forward MoL: it doesn't say much about the individual, and thus doesn't help guide their actions in any specific way. If one simply chooses happiness as their MoL, they risk skipping the deep act of self reflection that this question usually entails. In finding one's MoL, I think the process is more important than the result one comes to.
To have impact on the world: This is a common response among software developers in Silicon Valley and ambitious people in general. However, this response is sometimes a facade, covering their desire for power and responsibility. A similar response is to contribute back to society. A friend of mine is compelled to this because of all he feels that society has given him.
Reproduction: That we live to make offspring is irrefutably true if you look at our meaning from the biological lens, but I doubt that one could use this meaning to place themself on a fulfilling life, or to navigate through tough times. But who knows, maybe it'll change when I have a kid!
Alleviating suffering: This is a belief that nourishes the holder with meaning on gruelling paths such as medical residency, volunteering with Doctors without Borders, and religious pilgrimage.
Progress: Ray Dalio in his book Principles says that his meaning has come from making progress in his career and in having meaningful relationships. It seems that he states that progress for the sake of itself gives him meaning: not his career nor relationships, but the fact that they're getting better. For a time, I followed this meaning quite seriously. However I found that it made me less happy with what I had and overthink everything.
What's the purpose of making a frankenstein of mathematical symbols and vague words? At least I can say more in less space!
Let M be one's forward meaning of life.
Let π(x(t);M) be the policy induced by following one's MoL, when in the situation x(t). The semicolon in the function means that M is a parameter: it defines the function, whereas x(t) is something you put into it.
For example, if I receive a hug, my policy is to reciprocate. In this formulation, I haven't included constraints imposed by one's scenario. For example, Joe, age 30 and fresh out of his doctorate in climate science, can decide that his forward MoL is to save the environment. Without constraints, his policy would be to volunteer as an ice cap researcher. However, this action is constrained by him needing to support his young children.
Let τ be the trajectory of your life: all the places you'll be, all the choices you'll make. It is defined as (x(t), a(t)), two time-varying functions of your state and your action. Note that a(t) = π(x(t);M). The trajectory is determined both by π(M) and randomness in your environment (winning a lottery today doesn't mean winning again tomorrow!)
Let r(x(t), a(t); M) be your reward for doing action a(t) at state x(t). The reward can be, for instance, the sum of your feelings of satisfaction and fulfilment at the moment. Crucially, the reward that you experience depends on the meaning of life that you choose. For example, if you have to do something anyways, it's better to think that it's good for you than not. Say that two PhD students A and B are asked by their professor to TA. A sees it as a chore, but B's backwards MoL is to disseminate knowledge. Guess who's going to have a lower blood pressure by the end of the semester.
The forward meaning of life is simply (modelling life as a discrete set of actions and states)
M = argmax E[∑r(x(t),a(t); M)]
Where due to a lack of text-formatting I must here say that
This formulation is inspired by the mathematical framework of Reinforcement Learning (RL), which engineers use to build artificial intelligence that learns to make good decisions by interacting with an environment. For simplicity, I've omitted the "discount factor", which economists and RL engineers use to decrease the weight of rewards far into the future.
There are several themes that are important to this topic, but that I couldn't manage to weave into the text. The first is the fact it’s a privilege to ponder the meaning of life in the first place. There's no question that the agony of those who ask this question is real. However, I only realised during the re-writing of this article that not everyone is high-up enough on Maslow's pyramid to ask it.
Additional thoughts include:
Thinking, fast and slow: The theme of untruths is related to System 1 and System 2-type thinking from psychology, where the former refers to heuristics that we use for fast decision-making, and the latter to when we think carefully about things. It seems that believing in an untruth and keeping to it is system 1-type thinking, necessitated by the inability of our system 2 processes to come to a flawless answer. This article is the desperate effort of a system 2 process trying to convince other system 2 processes to trust in their system 1!
Off-policy versus on-policy learning for finding the forward meaning of life: Like humans, RL programs learn from experience and improve their policies over time. They have two different strategies for doing so: When following an on-policy strategy, the program can only learn to improve its policy when it's following it. On the other hand, off-policy strategies allow them to improve their policies by just observing the correlations between actions and rewards, even if they're following a random policy. I bring this up because without a MoL or a strong set of principles, many of our decisions are probably driven by moment; we go with the flow.
The off-policy method corresponds to someone coming up with their MoL just by reflecting on their experiences, whereas the on-policy approach corresponds to one deciding on their MoL by making their best guess and trying it out. I think that the on-policy approach to finding the forward MoL is far better suited for us human beings: it guides what we focus on and thus remember, and it pushes us to experience things that we never normally would have. With our limited time and memory, taking an on-policy approach to discovering our forward MoL can allow us to learn more about ourselves than we ever could relying on the randomness of an off-policy method.
I thank Damien, Fanny and Sarah for their comments and inspiration for the article. I also thank everyone else that's put up with me enjoying Socates’ method without forcing me to share his fate.
February 5th, 2023