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. 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. Edward Damer, in his book "Attacking Faulty Reasoning", describes what others might call a causal slippery slope but says,  Instead Damer prefers to call it the "domino fallacy". Howard Kahane suggests that the domino variation of the fallacy has gone out of fashion because it was tied the domino theory for the United States becoming involved in the war in Vietnam and although the U.S. lost that war "it is primarily communist dominoes that have fallen". Frank Saliger notes that "in the German-speaking world the dramatic image of "the dam burst" seems to predominate, in English speaking circles talk is more of the slippery slope argument" and that "in German writing dam burst and slippery slope arguments are treated as broadly synonymous. In particular the structural analyses of slippery slope arguments derived from English writing are largely transferred directly to the dam burst argument." In exploring the differences between the two metaphors he comments that in the dam burst the initial action is clearly in the foreground and there is a rapid movement towards the resulting events whereas in the slippery slope metaphor the downward slide has at least equal prominence to the initial action and it "conveys the impression of a slower 'step-by-step' process where the decision maker as participant slides inexorably downwards under the weight of its own successive (erroneous) decisions." Despite these differences Saliger continues to treat the two metaphors as being synonymous. Walton argues that although the two are comparable "the metaphor of the dam bursting carries with it no essential element of a sequence of steps from an initial action through a gray zone with its accompanying loss of control eventuated in the ultimate outcome of the ruinous disaster. For these reasons, it seems best to propose drawing a distinction between dam burst arguments and slippery slope arguments." Eric Lode notes that "commentators have used numerous different metaphors to refer to arguments that have this rough form. For example, people have called such arguments "wedge" or "thin edge of the wedge", "camel's nose" or "camel's nose in the tent", "parade of horrors" or "parade of horribles", "domino", Boiling Frog and "this could snowball" arguments.