And oftentimes to win us to our harm, / The instruments of darkness tell us truths; / Win us with honest trifles, to betray’s / In deepest consequence.—
Act I, Scene 3 · Banquo
Context
Banquo warns Macbeth that supernatural beings often tell small truths in order to lure people into trusting them before delivering destructive lies about more important matters.
Analysis
The phrase "instruments of darkness" distances the witches from direct agency—they're tools, not originators, which implies a larger evil using them. Banquo's syntax mirrors the deceptive process he's describing: "win us" appears twice, first with "truths" and "honest trifles," then with "betray," so the repetition enacts the bait-and-switch he's warning about. His metaphor of small truths as "trifles" used to "win us" economically captures how con artists work, framing belief as something that can be purchased cheaply and spent disastrously.
Essay Tip
Use this to argue that Banquo provides Macbeth (and the audience) with the interpretive key to the entire play—the witches' prophecies are structured like a con, where accurate small predictions buy credibility that gets cashed in on a fatal large one—and Macbeth's tragedy is that he ignores this warning.