Slippery Slope

The evaluation of an argument or proposition by reference chiefly, or only, to its extreme form.

The Fallacy of the Slippery Slope is pernicious and hard to argue against, except perhaps with a weary “Oh, don’t be ridiculous!” and a moment of mourning at the death of good faith and trust. The arguer insists that the thing he opposes, however innocent, would lead inevitably to its horrible extreme. A comforting hug leads to paedophilia; a dram of whisky to alcoholism; punishment to brutal assault; authority becomes harassment; military action is genocide; concern about genetic inheritance leads to Auschwitz; expression of erotic desire leads to rape; and, of course, without intrusive health and safety regulation, we would be on the slippery slope to a litany of battle, murder and sudden death. No activity is immune to this particularly vicious fallacy. The moderate is overwhelmed by the extreme.

Yet the use of the law to prohibit all activities with a horrible extreme would in due course prohibit everything. There is no activity—eating, sex, discipline, work, alcohol, religion, humour—which does not have a monstrous and extreme expression. There are, of course, occasions when the feared extreme case does actually happen, so it is necessary to draw the line between what is a negligible risk and what is not. Life is a network of such fine distinctions, and deciding how to respond to them is a matter of judgment.

Unfortunately, the slippery slope belongs to a class of fallacies which cannot tolerate paradox. The most relevant here is the Sorites Paradox, aka the “paradox of the heap” (Greek: soros heap). Imagine a heap of sand. Remove one grain. It is still a heap. Remove another, and another, until eventually it is only sort of a heap, or almost a heap, and finally it is evidently not a heap. There are transitions here, but no borderlines; our descriptions at each stage depend on judgments, and not on explicit rules: this is a “well, yes and no” world, open to debate.S33

But if the fuzziness of such transitions is not recognised, the argument snaps to the crude extremes: the moderate is only recognised in the terms of parody. Trust is derided as cringe and surrender, and all options for a post-industrial, post-market future are swept into a bin marked “going back to living in caves”, or “taking us back to the Dark Ages”. Reference to any time before the present is lumbered with Thomas Hobbes’ phrase “nasty, brutish and short”, as the argument settles comfortably into a contempt for the past which makes the present and its predicaments incomprehensible.S34

The slippery slope is a denial of judgment, but it can be tricky to avoid, because the alternative lacks finality. The critic William Empson knew this; the logic of considered moderation, of ambiguity, fuzziness and paradox, he wrote, commits us to “maintaining oneself between contradictions that can’t be solved by analysis”. In fact, that tolerance of vague borderlines is essential if we are to think about the hard times ahead. It will be necessary to explore solutions which, taken to the extreme, would be difficult to defend. Every little local stratagem will cast a shadow—a hint of the extreme glowering over the Lean Economy with hate and the threat of mayhem; but not paralysing it, for communities dominated by the slippery slope—lacking trust, moderation and judgment—will suffer natural deselection.S35


Related entries:

Institution, Reductio ad Absurdum, Systems Thinking, Damper, Hyperbole, Ironic Space.

« Back to List of Entries
David Fleming
Dr David Fleming (2 January 1940 – 29 November 2010) was an economist, historian and writer, based in London. He was among the first to reveal the possibility of peak oil's approach and invented the influential TEQs scheme, designed to address this and climate change. He was also a significant figure in the development of the UK Green Party, the Transition Towns movement and the New Economics Foundation, as well as a Chairman of the Soil Association. His wide-ranging independent analysis culminated in two critically acclaimed books, Lean Logic and Surviving the Future. A film about his perspective and legacy - The Sequel: What Will Follow Our Troubled Civilisation? - was released in 2019, directed by BAFTA-winning director Peter Armstrong. For more information, including on Lean Logic, click the little globe below!

Comment on this entry: