"Ralph! What is the physical nature of evil?" Hunter S. Thompson once asked. The illustrator Ralph Steadman has answered his late pal with a blistering caricature of Bush as a sword-wielding, oil-spewing demon. There's not much subtlety in this show, but that's not what illustration is forthe best illos deliver a clever visual argument demanding that you at least think about an issue. In this exhibit, Mirko Ilic imagines coffins as gas pumps, and Serge Bloch demarcates a soldier into "Chuck," "Sirloin," and "Tripe." Illustration functions as the opening salvo of debate: "Artists Against the War" delivers the op-ed page in the raw. Society of Illustrators, 128 E 63rd, 212-838-2560. Through January 26.