This article retraces the forgotten history of a theory of metaphor and blending. Such a theory has its roots in various philosophical, linguistic, and psychological reflections on metaphor production and comprehension, which reach from Locke's recognition that our basic mentalistic concepts are metaphorical, to Bühler and Stählin's psychological and experimental work on metaphorical blending in the 1930s. These early theories were forgotten after the positivist turn in psychology and the structuralist turn in linguistics. Analyzing these beginnings of a theory of blending might give modern theories firmer roots, roots that might prevent them from being swept away by the next wave of positivism and reductionism.