“Burn the Midnight Oil”: The Origin, Properly Sourced

The popular story

Ask where “burn the midnight oil” comes from and you will almost always be pointed to one man: the English devotional poet Francis Quarles, and one book: his hugely popular Emblemes of 1635. The line quoted is “Wee spend our mid-day sweat, our mid-night oyle; Wee tyre the night in thought; the day in toyle,” from Book 1, Emblem 12 (“Hugo de Anima”). The everyday explanation behind it is refreshingly literal: in an age lit by oil lamps, anyone still working after dark was quite literally burning oil, and a light under the study door at a late hour meant real labour.

What the record shows

Here the popular story holds up better than most. Quarles’s 1635 line really is the earliest verified appearance in print of the phrase “midnight oil” in the sense of late-night toil — it is cited by etymology references and the Phrase Finder alike. The literal explanation is sound too: oil lamps were the ordinary means of working after dark, and there was even a now-obsolete verb, elucubrate, for studying by lamplight. But there is a catch. Quarles wrote spend our midnight oil, not burn it. The exact modern wording is considerably younger: Merriam-Webster gives a first known use of “burn the midnight oil” in 1806, and an intermediate step survives in William Shenstone’s Elegy XI — “I trimm’d my lamp, consum’d the midnight oil” — printed in the later 1700s.

The verdict

Attested. The core of the story checks out: the phrase “midnight oil” for after-dark work is genuinely documented from 1635 in Quarles, and the imagery is literal rather than invented folklore. The one honest correction is that Quarles did not write the idiom in its modern form — he used “spend,” and the verb “burn” only becomes the standard companion in the early 1800s. So credit Quarles with the image, not the exact phrase.

What we don’t know

We do not know who first attached “burn” to “midnight oil,” only that the pairing was current by 1806. The two-century gap between Quarles’s “spend” (1635) and the recorded “burn” (1806) is thinly documented, and earlier uses of the full phrase may yet surface in digitised books. There is also minor textual noise around the Quarles line itself: online sources split between “our mid-day sweat, our mid-night oyle” and “…or mid-night oyle,” a difference of a single letter that reflects OCR and reprint variation rather than a settled reading.

How it changed

The expression travelled from a specific poetic image to a fixed idiom. Quarles’s “spend our midnight oil” gave way to “consume the midnight oil” in the 18th century and then to the durable “burn the midnight oil” by the early 19th. Once electric light arrived, the literal meaning vanished entirely — nobody burns oil to read anymore — yet the phrase survived precisely because it had become a metaphor for effort rather than a description of lighting.

Usage today

It remains fully current and neutral in tone, used for any hard late-night work: study, deadlines, overtime. “The team burned the midnight oil to ship the release on time.” Both “burned” and “burnt” are acceptable past forms, and the phrase carries a faint note of admiration — dedication, not merely lost sleep.