Reasons and Persons
by Derek Parfit

Derek Parfit was a British philosopher who specialised in personal identity, rationality, and ethics. He is widely considered one of the most important and influential moral philosophers of the late 20th and early 21st centuries. This book is his most famous work.

The first half of the book argues against self-interest theory, the idea that each person should seek the outcomes that would make their life go, for them, as well as possible.

Parfit argues that self-interest theory was a “feature” in hunter gatherer society that became a “bug” after the neolithic revolution when societies become larger and more interdependent. This meant your actions could affect people you didn’t know so the in-built feedback mechanism you would get that keeps you from directly harming people is no longer effective. For example, if you took some action which unintentionally harmed a good friend, you would see they were harmed, apologize and stop. When your actions harm someone you never interact with, there’s not feedback mechanism to stop you from continuing to create harm.

Parfit uses a thought experiment:

Imagine you have 1,000 torturers matched up with 1,000 prisoners.

When we see each torturer beat his prisoner, we are morally repulsed. With each blow, you can see the pain and anguish on the prisoner’s face.

Imagine now that instead of directly harming one prisoner, the torturers stands in front of a switchboard with 1,000 switches. Each time a switch is flicked on, it triggers an electrical shock which causes all 1,000 of the prisoners 1/1,000th of the pain they would have experienced from being individually tortured. This scenario is less morally repulsive and we tend to shrug it off because the effect on each person is very small. Observing a prisoner receiving a small shock does not create the same moral repulsion as a prisoner being ruthlessly beaten.

However, when this happens systematically and each torturer flicks a switch, you end up with the same outcome. All the prisoners endure as much pain as if they had been individually beaten.

Parfit argues this is what is happening in the world today. We are plagued by coordination problems where everyone is doing small amounts of harm to everyone else, making us all worse off, without triggering the moral repulsion reflex. As one example, you could imagine a factory which pollutes a river making the water very slightly worse for everyone downstream.

Parfit advances Critical Present Aim Theory, which if you’re really curious, I recommend you just read the book because it would take me about fifty pages to unpack (if I am even capable). 🙂

The second half of the book further attacks self-interest theory by arguing that there is no such thing as “the self” as most modern people conceive of it. Am I, in this moment, more similar to you, in this moment, as I am to “me” ten years ago? Parfit argues I am not and that self is a construction based on a false belief in Cartesian dualism.

Imagine it is possible to surgically meld your brain and body with Napoleon’s brain and body. At what percentages do you become Napoleon or does Napoleon become you?

If you go from 50% you/50% Napoleon to 50.1% You/49.9% Napoleon and the only difference is that the resulting person no longer likes to eat tomatoes, does that make the resulting person you, Napoleon or someone else?

Parfit is clearly brilliant and has some great thought experiments to walk you through his arguments, but make no mistake that Reasons and Persons is still a difficult read.

At the end of the day, Parfit largely succeeds in proving the illusions of the self through formal logic, a much different, but complementary approach, to buddhist teachings and meditation.

He offers some suggestions for how we should behave differently if we accept his conclusions which weren’t particularly satisfying and many of which I disagreed with in part or whole.

Parfit is a consequentialist, an ethical theory I have historically subscribed to, but have been drifting away from the past few years. Reading Reasons and Persons actually seemed to accelerate that drift.

The biggest thing I took away was from a moving and compelling argument for (future) self-compassion. We are often harder on ourselves than other people, because we believe it is ethical to be mean or hard to ourselves but not others. However, if you accept that future you is a different person than present you in the same way a friend is a different person than present you, you have to agree with Parfit that “We ought not to do to our future selves what it would be wrong to do to other people.”

If you really want to think about ethics, consequentialism, and/or self-interest theory, this is the book for you. Part 3 on the notion of “self” being a false construct is both the best part and the easiest to read so you might start there.

Amazon link: Reasons and Persons

Last Updated on April 18, 2019 by RipplePop