Both halves sound prudent when read aloud. The slogan omits the apparatus that makes either half executable, and the cost of the slogan is paid by the managers who try to follow it without one.
1. The claim as it is usually told
The rule is two clauses. Hire slowly: take your time, meet the candidate multiple times, run the references, never hire out of desperation. Fire fast: when you know the hire was wrong, do not extend the probation — remove them. The slogan is treated as a single law of organisational health. Slow hiring protects against a thousand wrong decisions. Fast firing protects against the one wrong decision you did make compounding. In the telling, both halves are uncontroversial. Both halves appear in business books, blog posts, and founder interviews as if they were observed laws.
2. Where it originated as far as can be established
The clearest primary codification is Brad Smart's Topgrading (2005), which sets out the "A" player hiring methodology and uses both phrases in the methodology's own lexicon. The lineage is older and the phrasing overlaps with management writing attributed to Andy Grove and to a school of mid-twentieth-century industrial psychology. The phrase as it travels — short, symmetrical, slogan-shaped — does not appear in the primary management literature in those exact words; it is a compression. The compression travels because it is portable and because both halves sound prudent when read aloud.
3. What it left out
Two preconditions. First, the rule presumes a deep applicant pool and a hiring process long enough to test for fit across multiple signals. Most operating teams — early-stage companies, small professional firms, owner-operated businesses — have neither. The candidate you need is the candidate someone else will hire while you run four more interviews. Hire slowly in those conditions is don't hire. Second, the rule presumes a documented discipline for what counts as a "wrong" hire and a legal apparatus that makes removal tractable. Fire fast in the absence of clear documentation, in jurisdictions with employee protections, or in teams of fewer than twenty people, is a lawsuit you walk toward. The slogan omits the apparatus it requires. The slogan also omits the cost of the slow process in the form of unfilled seats and the cost of the fast process in the form of demoralised teams.
4. The counter-example
The companies that scaled fastest in the last twenty years did not, in general, hire slowly. Amazon, Netflix, Salesforce, and most of the consumer-internet category hired aggressively to capture windows that would close; many of their executive teams include "fast hires" who were promoted inside. Conversely, a meaningful share of bad hires were retained past the point at which the manager knew, on the slogan, they should have been let go — because firing was costly, because the team was small, because the manager was uncertain. The slogan is symmetrical in print and lopsided in practice: it makes firing sound free, when firing is the most expensive single act a manager performs. Reed Hastings's discussion of the Netflix culture memo and the "keeper test" is closer to a working version of the rule than the slogan; Hastings was explicit about the cost of the retained bad hire, but also explicit that the keeper test was the discipline, not the slogan.
5. What the honest version would be
Don't hire out of desperation. Don't keep someone you know is wrong for the seat, once you have the documentation to act. Two clauses, less slogan-ready, both halves true. The first half is about the manager's state of mind; the second is about the manager's record-keeping. Neither is captured by the original formulation. The slogan is a way of sounding decisive about a category of decisions that are, in practice, expensive and slow. The honest version admits that.