Parfit in Seven Parts




Derek Parfit was a great philosopher, but his work is not known for being especially approachable. Reasons and Persons was 500+ pages of incredibly dense (yet rewarding!) philosophy. The three volumes of On What Matters total almost 2000 pages. Very few people will (or should) read all this. In Parfit’s Ethics, I critically introduce Parfit’s central insights and arguments in around 130 pages (according to my preprint; Cambridge University Press somehow squeezes this into just 55 pages). But even this very short book is still, you know… a book… and so unlikely to be as widely read as random blog posts on the internet. Solution: turn the book into a series of blog posts!

So, here we are. I’ve written seven posts that break down different elements of Parfit’s thought into manageable chunks. (The first six draw heavily from my book; the seventh, on metaethics, contains more new material.) I hope this will prove valuable to philosophers, students, and philosophically-interested readers who would like to learn more about Parfit’s ideas without requiring a huge investment of time and effort. If some of your friends might meet this description, do them a favour and let them know of this resource!


Table of Contents


Good Thoughts
Against Egoism and Subjectivism
In the spirit of encouraging broader appreciation of Parfit’s work, I’m planning a short series of posts, Parfit in Seven Parts, drawing from my book on Parfit’s Ethics. This first post will introduce Parfit’s arguments for thinking that we objectively ought to care about others’ well-being (no matter what desires we might have to begin with…

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Good Thoughts
Priority and Aggregation
To continue my Parfit series (see Part I here), today’s topics are (i) priority and (ii) aggregation. Equality vs Priority vs Diminishing Marginal Value Suppose you could bring some extra happiness to either Joy (who is already pretty happy) or Misery (who is not). It seems like you ought to benefit Misery, even if you could give slightly more extra happ…

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Good Thoughts
Rational Irrationality and Blameless Wrongdoing
As Parfit defines it, a theory T is “indirectly individually self-defeating when it is true that, if someone tries to achieve his T-given aims, these aims will be, on the whole, worse achieved.” Put aside cases in which the agent fails due to personal incompetence or ignorance. The more interesting cases of indirect self-defeat are ones in which merely p…

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Good Thoughts
Parfit’s Triple Theory
Parfit’s central project in On What Matters is to argue that the best forms of Kantianism, Contractualism, and Rule Consequentialism converge, forming a unified view that he calls the “Triple Theory”. These three theories have traditionally been seen as rivals. Rule Consequentialism directs us to consistently follow whatever rules would be impartially b…

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Good Thoughts
Do you really exist over time?
Parfit argues that we do not endure, or exist through time, in quite the way that we ordinarily suppose. He further argues that “identity is not what matters,” as one might split into multiple future “selves” (in the relevant sense) without any of them truly being one and the same person as oneself. Such claims initially sound incredible. But, as we wil…

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Good Thoughts
The Birth of Population Ethics
Parfit introduced two problems—the Non-Identity Problem, and the Repugnant Conclusion—that have perplexed philosophers ever since. The Non-Identity Problem An individual’s existence is fragile—not in the sense that they are easily killed, but in the less-appreciated sense that they very easily might never have existed in the first place. We’ve all heard t…

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Good Thoughts
Moral truth without substance
Previous entries in this series [parts I, II, III, IV, V, and VI] surveyed Parfit’s first-order normative views. In this final post, I’ll highlight some of Parfit’s key ideas and arguments in metaethics (esp. the nature of normativity). Parfit’s moral realism: objectivity without ontology…

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I’ll conclude by sharing Parfit’s own concluding comments, on what he took to matter most:

One thing that greatly matters is the failure of we rich people to prevent, as we so easily could, much of the suffering and many of the early deaths of the poorest people in the world. The money that we spend on an evening’s entertainment might instead save some poor person from death, blindness, or chronic and severe pain. If we believe that, in our treatment of these poorest people, we are not acting wrongly, we are like those who believed that they were justified in having slaves.

Some of us ask how much of our wealth we rich people ought to give to these poorest people. But that question wrongly assumes that our wealth is ours to give. This wealth is legally ours. But these poorest people have much stronger moral claims to some of this wealth. We ought to transfer to these people… at least ten per cent of what we inherit or earn.

What now matters most is how we respond to various risks to the survival of humanity. We are creating some of these risks, and we are discovering how we could respond to these and other risks. If we reduce these risks, and humanity survives the next few centuries, our descendants or successors could end these risks by spreading through the galaxy.

Life can be wonderful as well as terrible, and we shall increasingly have the power to make life good… Some of our successors might live lives and create worlds that, though failing to justify past suffering, would have given us all, including those who suffered most, reasons to be glad that the Universe exists.

Originally appeared on Good Thoughts Read More