 There is another group of criticisms coming from the careful study of the history of science: Hanson (1958), Feyerabend (1962) and Kuhn (1962) aimed to show that observation concepts are theory-laden in a manner that makes their meaning theory-dependent. Feyerabend’s (1978: 32), for example, held that all terms are theoretical. Hanson (1958: 18) thinks that Tycho and Kepler were (literally) ‘seeing’ different things when perceiving the sun rising because their astronomical background theories were different. Kuhn (1962) was more tentative when expounding his variant of the theory-ladenness of observation. In a discussion of the Sneed formalism of the structuralist school, he favored a theory-observation distinction that is relativized, first to a theory and second to an application of this theory (Kuhn 1976).