The Fechner-Brentano controversy on the measurement of sensation

The purpose of this paper is to provide an overview of Brentano's critique of Fechner's psychophysics. An attempt is made to show that, far from being a mere historical curiosity, the dispute with Fechner is of strategic importance for Brentano's theory of sensation. I defend the view that Brentano not only raised strong objections against the logarithmic law, but also sought to lay new foundations for the idea of a psychophysical measurement set forth by Fechner in his Elements of Psychophysics. In the first section, I briefly review some facts about Fechner's psychophysical law and discuss two corrections proposed by Brentano. In the second section, I examine some further, more general objections. In the final section, I then show how Brentano's late theory of "sensory spaces" could be viewed as a positive contribution to the psychophysical problem as posed by Fechner.