Slippery slope

The metaphor of a "slippery slope" conjures up images of the danger of coming too close to the edge of a cliff. One step in itself may not cause you any harm, as it merely brings you down the slope a bit. But if you take enough steps toward the brink, you will reach a point where the slippery ground makes you lose your balance and tumble down over the precipice.

In rhetoric, a "slippery slope argument" is one which suggests that an innocent-seeming small action will lead inevitably to a disasterous result.

Examples:

• If we allow this increase in administrative fees, soon tuition will double!
• If we don't stop the terrorists in Iraq, they'll invade Maine next!
• If we send in 100,000 troops, the next thing you know we'll be in a quagmire like Vietnam!
• If we let gays get married, soon men will want to marry their kitchen appliances!

This sort of argument is generally recognized as a logical fallacy.

Quotations illustrating use

Literal

Even when I was on this mare, she would poise herself on the top of a block of granite, with her four feet close together in the manner of a goat and she leaped across crevasses of unknown depth after having to go down a slippery slope on one side, and when, on the other, she had nothing to jump upon except steeply-inclined blocks of stone.—"Himalayan Ponies," The New York Times, March 14, 1875, p. 4

They stood, who saw the future come

On through the fight’s delirium!

They smote and stood, who held the hope

Of nations on that slippery slope

Amid the cheers of Christendom.

Will Henry Thompson (1888), "The High Tide at Gettyburg"

Metaphorical

It is not with them we are concerned: they will not be taught or reformed; so, they will go down the steep and slipperly slope on which the heartless move, to perdition!

—Bernard O'Reilly, 1883

Is there one among us who is tempting a brother man to dishonesty, to drink, to lust; who is pushing some thoughtless girl down the steep and slippery slope which ends--we know where? Then let him stop and listen, not to me, but to Christ.

George Jackson (1903), The Teachings of Jesus

The cry for the rates in addition to the taxes has been going up from the clerical for years. But they were warned by the late Archbishop of Canterbury not to attempt it, for as surely as they succeeded they would lose their control of their sectarian schools. They would be on the "slippery slope," he said, in a characteristic phrase. However, they have taken the plunge, and the Education Acts of 1902 and 1903 are the results.

—John Clifford, 1905

We cannot give up any portion of our claim until the question of interallied debts has been settled. We have the right and duty to guarantee ourselves against the possibility of a diminution of our claim by the international financiers.... If today Germany obtained any remission of her debt she would profit.... It was by far the wisest policy to hold fast at the top of that slippery slope."

—French premier Raymond Poincaré, Nov. 16, 1923

The key task of the phrasedick is to find earliest uses of ["slippery slope"] in its present sense of "a course that leads inexorably to disaster." The OED tracks it to a 1951 novel, but new retrieval technology lets us do better than that.... we have this 1857 use from Chambers' Journal: "When the educated person of the middle class is reduced to pennilessness... what but this gives him the desire to struggle again up the slippery slope of fortune?"

In both of these citations, the meaning is closer to "the greasy pole...." The current sense... probably surfaced in the early 20th century, possibly in an article by a writer in a 1909 Quarterly Review, published in London: "the first step down that slippery slope at the bottom of which lies a parliamentary government."

—William Safire, 2002

See also

• Non Causa Pro Causa