He would have made a good BUTCHER but for the by-blow

Insights

Flaw that ruins fitness

Like a butcher who should dispatch with one clean stroke, the person has a near-perfect profile but adds an unnecessary ‘extra blow’ that betrays incompetence or cruelty.

Collateral damage

The ‘by-blow’ stands for side effects—spiteful asides, needless risks, or overkill—that turn capable action into harm, undermining otherwise solid work.

Incontinence of desire

Reading ‘by-blow’ as ‘illegitimate child,’ the line satirizes lack of self-restraint: private excess exposes a public defect of character that unfits a man for trusted roles.

Overdoing the deed

The type cannot stop at ‘enough’; a compulsion to add more—another cut, another word—ruins precision and stains reputation.

Craft ethics of the single stroke

Traditional slaughter valorized a swift, clean kill; a second or sideways stroke (‘by-blow’) marked botched craft. The proverb borrows this ethic to measure character by restraint at the point of impact.

Pun on ‘by-blow’

Early English used ‘by-blow’ for both a side-stroke and a bastard child. The joke’s doubleness widens application—from technical ineptitude to sexual indiscretion as parallel failures of control.

From trade to temperament

Occupational imagery (butcher) becomes a moral assay: the capacity to do only what is necessary—no more, no less—signals mastery in work and in conduct.

Social risk of the ‘extra’

Many fiascos are born not of lack but of surplus: extra force in justice becomes cruelty; extra zeal in talk becomes insult. The ‘by-blow’ names that surplus that flips virtue into vice.

Comic severity

The line mocks with a wink—‘he’d be excellent, except for the one thing that makes him unfit’—using humor to make the critique digestible and memorable.

Rhetorical Devices

Paronomasia

Plays on the double sense of ‘by-blow’ (side-stroke/bastard), letting a single word carry technical and moral censure.

Irony

Praises with faint condemnation: the supposed compliment (‘would have made a good butcher’) is canceled by the very trait that proves the opposite.

Metonymy

‘Butcher’ stands for any role requiring decisiveness with restraint; the trade becomes a cipher for character.

Antithesis

Balances ‘good butcher’ against ‘by-blow’ to dramatize how one small excess overwhelms broader competence.

Alliteration

The b-sounds in ‘butcher’ and ‘by-blow’ give the epigram snap and mnemonic bite.