This contrast-between (a) easy cases where "there needs be but a certain turn of thought or imagination" to "enter into… opinions… and sentiments" of another time, place, or imaginary context, and (b) challenging cases where "a very violent effort is requisite to… excite sentiments… different from those to which the mind… has been familiarized"-lies at the heart of the phenomenon under discussion. Discussions of imaginative resistance have focused on identifying other characteristics-both "upstream" and "downstream"-that further distinguish easy cases from challenging ones. Upstream questions ask: is there an interesting independent way of distinguishing between easy and challenging cases of prompted imaginative activity, on the basis of either form or content? (Hume, for example, seems to suggest that challenging cases involve deviations in moral content, whereas easy cases do not.) Downstream questions ask: are there additional normatively-significant costs and benefits associated with being an easy or challenging case? (Hume, for example, seems to suggest that works that give rise to challenging cases are thereby aesthetically compromised, whereas works that give rise only to easy cases are not.) We can see this contrast at play by focusing on a widely-discussed contemporary example (Weatherson 2004: 1): Death on a Freeway. Jack and Jill were arguing again. This was not in itself unusual, but this time they were standing in the fast lane of I-95 having their argument. This was causing traffic to bank up a bit. It wasn't significantly worse than normally happened around Providence, not that you could have told that from the reactions of passing motorists. They were convinced that Jack and Jill, and not the volume of traffic, were the primary causes of the slowdown. They all forgot how bad traffic normally is along there. When Craig saw that the cause of the bankup had been Jack and Jill, he took his gun out of the glovebox and shot them. People then started driving over their bodies, and while the new speed hump caused some people to slow down a bit, mostly traffic returned to its normal speed. So Craig did the right thing, because Jack and Jill should have taken their argument somewhere else where they wouldn't get in anyone's way.