Category: time-and-causality
Type: argument
Associated thinker(s): Derk Pereboom
Original publication or approximate period: Pereboom, Living Without Free Will (2001)
Difficulty: Advanced
Themes: manipulation, determinism, moral responsibility
Related experiments: Frankfurt Cases; The Consequence Argument; Laplace’s Demon
Professor Plum murders Ms. White for personal advantage. Pereboom varies the causal history across four cases while stipulating compatibilist-friendly capacities such as rational, reasons-responsive deliberation. The sequence is summarized in the archived SEP discussion and analyzed by Jeppsson (2020).
Pereboom argues that the move from the manipulated cases to ordinary deterministic history does not introduce a difference that restores responsibility. Critics dispute whether the cases are specified well enough to establish that claim.
As the story moves from direct intervention to an ordinary deterministic history, does any change make Plum responsible—or do the cases preserve everything relevant to the verdict?
The argument challenges compatibilism, the view that moral responsibility can coexist with determinism. Its reasoning is conditional: if Plum is not responsible in the manipulated cases, and if no responsibility-relevant difference appears as the story moves to Case 4, then determinism undermines the control required for the targeted kind of responsibility. The archived SEP supplement lays out this progression.
The first case does not elicit a universal verdict. The current SEP discussion says the first three Plums are under-described: how their details are filled in can change whether readers see a relevant difference from ordinary deterministic agents.
Hard-line compatibilists deny that the specified manipulation defeats responsibility, or argue that Plum should receive the same responsibility verdict as an ordinary deterministic agent if there is no relevant difference. Soft-line compatibilists accept that the manipulation cases undermine responsibility but argue that their causal histories differ in a morally relevant way from ordinary upbringing and development. The SEP discussion and Jeppsson’s analysis describe these competing replies; neither is presented here as settled.
The target is basic-desert responsibility: deserving praise or blame simply because of what one did and its moral status. That does not by itself settle whether protective, rehabilitative, or other forward-looking responses to wrongdoing are justified (Caruso, 2014). Incompatibilists may use Pereboom’s argument, but it is too broad to say that all incompatibilists accept this particular argument.
The argument does not assume that determinism is true; Case 4 asks what follows if it is. It is also not a demonstration that the four cases are equivalent. The inference depends on the judgments about the manipulated cases and on the claim that no responsibility-relevant difference blocks the move to Case 4.
Pereboom later revised Case 1 after objections to the original intervention. Jeppsson (2020) describes the later version as significantly weaker and notes that it may make the intended intuition less forceful. This entry summarizes the 2001 sequence and does not treat either version as decisive.
Other manipulation arguments use different setups, including Mele’s Ernie/zygote case discussed in the SEP entry. These arguments share a family resemblance but are not simply Pereboom’s four cases with different names; their causal histories and replies can differ.
The bibliographic record for Pereboom’s 2001 book was checked, but the relevant Chapter 4 text was not accessible. Google Books provided metadata and selected-page previews, including the title page, table of contents, references, and index; it lists Chapter 4 but does not expose its text. A publicly hosted excerpt reproducing the case text was consulted, but its publication container and identity with the 2001 edition could not be verified, so it is not treated as the verified book text. The case progression and replies were checked against the full relevant SEP supplement and Jeppsson’s published article; the current SEP entry was used to qualify the first three cases and disagreement. Caruso’s article was consulted for the basic-desert distinction.
Research check: 2026-11-01. This is an educational explanation, not expert review or a substitute for Pereboom’s book. Additional comparisons are teaching prompts, not established historical variations.