Editing Slippery slope (section)

===Thin end of a wedge===
Walton suggests Alfred Sidgwick should be credited as the first writer on informal logic to describe what would today be called a slippery slope argument.<ref name="Walton 2015" />{{rp|275}} Sidgwick wrote in 1910: <ref>{{cite book |last=Sidgwick |first=Alfred |title=The Application of Logic |location=London |publisher=[[Macmillan & Co.]] |date=1910 |page=40 |url= https://www.archive.org/stream/applicationoflog00sidgiala?ref=ol#page/40/mode/2up |access-date=2017-03-16}}</ref>
{{Blockquote|1=We must not do this or that, it is often said, because if we did we should be logically bound to do something else which is plainly absurd or wrong. If we once begin to take a certain course there is no knowing where we shall be able to stop within any show of consistency; there would be no reason for stopping anywhere in particular, and we should be led on, step by step into action or opinions that we all agree to call undesirable or untrue.}}

Sidgwick says this is "popularly known as the objection to a thin end of a wedge" but might be classified now as a decisional slippery slope. However, the wedge metaphor also captures the idea that unpleasant end result is a wider application of a principle associated with the initial decision which is often a feature of decisional slippery slopes due to their incremental nature but may be absent from causal slippery slopes.