Well, no, it's not. History is full of the real thing. 
"Slippery slope" is a logical fallacy as well.
Well, no, it's not. History is full of the real thing.
Not really. 'Slippery slope' is actually a horse-sense term used to describe how hard it is to get back to the top of a hill once you've started a downward course. It's a truism, not a fallacy. It holds in physics, biology, warfare, religion, and politics. Slippery slope is the mechanism of liberalization.