We present a historical account of the story behind the famous hawk/goose experiments of Lorenz and Tinbergen in a wider context of cognitive ethology. We discuss their significance, for ethological experimentation in general, and specifically for understanding innate constraints on cognition. As examples of the continuing significance of the hawk/goose paradigm of selective habituation, we discuss its relation to "exposure therapy" of human phobias and the use of hawk silhouettes as deterrents for songbirds. Finally we rephrase Uexküll's thesis of taxon-specific worlds ("Umwelten") as a "Theory of World." 2011 APA, all rights reserved