Perry’s Dialogue on Personal Identity and Immortality

What is the central question in Perry’s Dialogue on Personal Identity and Immortality?

Whether Gretchen Weirob can have a reasonable, philosophically coherent idea of surviving her own death—i.e., what personal identity consists in, and whether survival after death is possible under any theory.

Who are the three main characters in Perry’s dialogue and what roles do they play?

Gretchen Weirob (skeptical philosopher facing imminent death), Sam Miller (religious friend defending soul-based survival), and Dave Cohen (philosopher exploring memory and psychological continuity theories).

Why does Weirob insist on a "reasonable belief" regarding survival?

She rejects blind faith and wants a logically coherent account of how the very same person—not just a similar or duplicate one—could survive death.

What is Miller’s Soul Theory of personal identity?

Miller claims personal identity = sameness of soul; souls are immaterial, survive bodily death, and thus personal survival after death is possible.

What is Weirob’s main epistemic objection to Soul Theory?

Souls are invisible and undetectable, so we cannot confirm sameness of soul across time—making soul-based identity impossible to verify.

Why does Weirob use the “key and lock” analogy against Soul Theory?

A key fitting a lock daily doesn't prove it’s the same key, only that it behaves similarly; likewise, similar behavior doesn’t prove the same soul exists—identical souls could produce identical behavior.

What is Weirob’s conclusion regarding Soul Theory and personal identity?

Soul Theory fails because identity of souls is fundamentally uncheckable; thus it cannot ground a reasonable belief in survival.

What is the basic Locke-inspired Memory Theory of personal identity?

A future person is the same person as you if they can consciously remember your experiences.

Why does memory initially seem to work better than the body or soul for recognizing personal identity?

People identify themselves daily by memory, not by inspecting their bodies or souls; memory provides psychological continuity.

What is Weirob’s “real memory vs apparent memory” objection to Memory Theory?

People can have apparent memories (dreams, hypnosis, confabulations), but determining real memories already presupposes knowing the person who had the experience. That makes memory theory circular.

Why is Locke’s Memory Theory considered circular, according to Weirob?

It requires personal identity to determine which memories are genuine, yet those same memories are used to define personal identity.

What is Cohen’s Causal Memory Theory?

A memory is real if it is caused in the appropriate way by the original experience—e.g., via the continuous, genuine brain process that produced the memory.

How does Causal Memory Theory attempt to avoid circularity?

It defines real memory via causal connections rather than by presupposing personal identity, so the memory can ground identity rather than depend on it.

What is Weirob’s duplication objection to Memory (or Psychological) Theory?

If God creates two perfect psychological duplicates with identical memories, both satisfy the memory criteria, but both cannot be the same person; thus memory (even causal memory) cannot constitute personal identity.

Why does duplication show that memory cannot be identity?

Identity is one-to-one, not one-to-many; but psychological continuity can be duplicated. Therefore, memory is insufficient for identity.

What is the Julia North brain transplant case, and how does Cohen use it?

Julia North’s brain is placed in Mary Beaudine’s body; the resulting person has Julia’s memories and personality. Cohen argues the survivor is Julia because identity follows the brain/mind.

How does Weirob respond to the Julia North case?

She claims it is Mary’s body that survives, now operating with Julia’s brain—identity follows the body, not the brain; apparent memory similarities do not prove identity.

What is Weirob’s Body Theory of personal identity?

Personal identity consists in continuity of the living human body (or organism), not in memories, souls, or brain continuity.

What point does the brain-rejuvenation example aim to show?

Even if a new brain is created with all of Weirob’s memories and character, duplication is possible; thus such psychological copies cannot be identical with Weirob.

How does duplication challenge both memory and brain theories?

Both rely on psychological or neural patterns, which can be reproduced; but identity cannot be duplicated, so these theories fail to provide necessary one-to-one identity conditions.

What is Cohen’s final proposal regarding "what matters" in survival?

Psychological continuity—someone in the future thinking your thoughts, remembering your life, and pursuing your projects—may matter more than strict personal identity.

Why does Weirob reject Cohen’s “what matters” suggestion?

She insists that genuine survival requires being the same person, not merely having a psychologically continuous successor; without identity, there is no survival.

What is the difference between personal identity and psychological continuity?

Personal identity requires being numerically the same individual; psychological continuity involves mental connections (memories, intentions, character) that can exist without strict identity, especially under duplication.

What is the difference between numerical and qualitative identity?

Numerical identity = being one and the same entity.
Qualitative identity = sharing similar properties.
Duplicate persons would be qualitatively identical but not numerically identical.

What distinguishes real memories from apparent memories according to Causal Memory Theory?

Real memories are causally connected to the original experience through the appropriate internal brain processes; apparent memories are not.

Why is identity not the same as similarity?

A perfect copy may be similar or qualitatively identical but is not the same individual; identity requires one-to-one persistence over time.

What is the “epistemic problem” for soul theory?

We have no way of knowing or verifying whether the same soul continues over time, since souls are unobservable and behavior does not reliably indicate sameness.

What is the “metaphysical problem” for duplication-based objections?

If psychological states can be duplicated, then no psychological criterion can guarantee unique identity; identity must be one-to-one, not one-to-many.

What is John Locke’s key contribution to personal identity theory?

Locke argued that personal identity consists in continuity of consciousness—specifically, memory continuity—rather than substance (soul or body).

How does Perry’s dialogue relate to Locke’s theory?

It tests Locke’s Memory Theory, exploring its circularity, the real vs apparent memory distinction, and duplication problems.

What is the significance of Locke for modern personal identity debates?

He shifted focus from substance-based identity (soul/body) to psychological continuity, influencing contemporary analytic philosophy.

What is the philosophical purpose of the “key analogy” used by Weirob?

To argue that identical behavior doesn’t guarantee identical underlying substance (soul), just as a copy of a key can behave like the original without being it.

How do dreams, hypnosis, and confabulation challenge simple memory theory?

They produce apparent memories that feel real but lack genuine historical connection, showing memory alone cannot determine identity.

What does the brain-switching example illustrate about body theory?

It tests whether identity follows the brain/mind or the body, forcing a choice between psychological and bodily continuity.

Why do duplication scenarios pose a major challenge to psychological theories?

Because perfect duplicates can share psychological features, but identity cannot split; therefore, psychological characteristics cannot constitute identity.

Why does Perry’s dialogue suggest identity may not be what matters in survival?

Because psychological continuity seems to capture the practical concerns of survival (projects, memories, values) even when strict identity fails under duplication.

What is Weirob’s ultimate stance on personal survival?

She rejects soul, memory, and psychological theories; insists on bodily identity; concludes that survival after death is not possible for her.