Holmes’s Methods as Prompts(3)

Sherlockian Way of Thinking

5. Abduction: Elicit Most Natural Explanation

Abduction selects the most plausible explanation for the data at hand. Unlike deduction (certainty) or induction (generalization), abduction works in the realm of best-fit narratives under uncertainty—ubiquitous in investigation, diagnosis, and everyday inference.

In A Study in Scarlet, confronted with “Rache” scrawled in blood and a peculiar arrangement of signs, Holmes rejects ordinary robbery or chance violence; the ensemble is better explained by vengeance. Not because the theory is axiomatically true, but because it most economically accounts for the observed facts.

As prompts, abduction is ideal when no unique answer exists: fix the result, invite multiple competing explanations, and compare their likelihoods or trade-offs.

Prompt strategy: Hold Outcome Constant, Vary Story

Present the observed result.

Solicit candidate explanations.

Compare plausibility and implications; pick or rank.

Examples

Cart abandonment: Same outcome, segment explanations by psychological vs. price/logistics vs. technical factors.

Disappearing protagonist: Offer two backstories that best explain the final vanishing; compare emotional credibility.

Ambivalent review: “Fast shipping, never again.” Generate two likely service journeys and pinpoint the inflection where sentiment flipped.

Intermittent 404s: List three likely causes; for each, provide mechanism and remedy.

Bottom line

Abductive prompts grant the model “license to explain.” Instead of insisting on one answer, you ask for the best-fitting story—Holmes’s daily craft.

6. Retroduction: Give Result, Work Back to Cause

Retroduction (reverse inference) starts from the result and reconstructs the chain of events or causes that could have produced it. If hypothetico-deduction moves forward from “if,” retroduction moves backward from “thus.”

In “The Five Orange Pips,” Holmes notices that three deaths follow the receipt of envelopes containing orange pips. Taking the shared outcome—death—he searches back for an underlying mechanism: systematic intimidation followed by execution. Asking first “what summoned this result?” rather than “who?” lets him recover the story in reverse.

As prompts, retroduction excels in root-cause analysis, narrative reconstruction, debugging, and historical explanation.

Prompt strategy: Start at End, Rebuild Path

State the outcome crisply.

Ask for possible preceding causes/scenarios.

Have the model order stages or highlight the pivotal step.

Examples

Negative review retold: Break a likely journey into three stages, adding probable emotions and friction at each.

Plot backward: Given the midnight departure, outline five days that inevitably lead there, with one key event and one emotional turn per day.

Performance dip: “Latency rose 40% for two days.” List ≥3 causes; for the likeliest, propose a drill-down plan.

Policy backfire: Night-fare discounts lowered satisfaction; give three reasons and the institutional contexts that could produce each.

Bottom line

Retroductive prompts make the model “rewind time,” assembling process structure from a terminal state—one of Holmes’s favorite maneuvers.