Although the Branch‑Line Case makes it clear that the Replica is not numerically identical to the or… — Derek Parfit

Although the Branch‑Line Case makes it clear that the Replica is not numerically identical to the original person, Parfit denies the natural assumption that the original’s prospect on the Branch Line is almost as bad as ordinary death and claims instead that being destroyed and replicated is about as good as ordinary survival; this sets up his later, broader argument that identity is not what matters.

By Derek Parfit, from Les raisons et les personnes

Key Arguments

After establishing that he and his Replica are distinct persons—'he is one person, and I am another'—Parfit notes the intuitive reaction: 'If we believe that my Replica is not me, it is natural to assume that my prospect, on the Branch Line, is almost as bad as ordinary death.'
He explicitly announces that he will reject this natural assumption: 'I shall deny this assumption.'
He then states his key evaluative claim: 'As I shall argue later, being destroyed and Replicated is about as good as ordinary survival.' This foreshadows his reductionist view, where psychological continuity without strict identity can ground what prudentially matters.
By distinguishing numerical identity from what is 'about as good as ordinary survival', Parfit implies that the prudential value of survival does not strictly depend on continued existence of the same metaphysical subject.
Calling the simple case 'being destroyed and Replicated' connects the Branch‑Line narrative back to Simple Teletransportation, indicating that the evaluative claim applies not just to the overlapping‑lives scenario but to teletransportation more generally.

Source Quotes

And when I am dead he will live for another forty years. If we believe that my Replica is not me, it is natural to assume that my prospect, on the Branch Line, is almost as bad as ordinary death. I shall deny this assumption.

If we believe that my Replica is not me, it is natural to assume that my prospect, on the Branch Line, is almost as bad as ordinary death. I shall deny this assumption. As I shall argue later, being destroyed and Replicated is about as good as ordinary survival.

I shall deny this assumption. As I shall argue later, being destroyed and Replicated is about as good as ordinary survival. I can best defend this claim, and the wider view of

At the end of my story, my life and that of my Replica overlap. Call this the Branch-Line Case. In this case, I cannot hope to travel on the Main Line, waking up on Mars with forty years of life ahead.

Key Concepts

If we believe that my Replica is not me, it is natural to assume that my prospect, on the Branch Line, is almost as bad as ordinary death.
I shall deny this assumption.
As I shall argue later, being destroyed and Replicated is about as good as ordinary survival.
Call this the Branch-Line Case.

Context

Closing lines of Section 75’s excerpt, where Parfit draws a preliminary moral from the Branch‑Line Case, signalling his later reductionist thesis that what matters in survival can be preserved without numerical identity and that teletransportation can be 'about as good as' ordinary survival.