In this presentation, I deal with four issues related to Harvey’s quantitative argument. Firstly, I present (together with Dagmar Provijn) an account of the discovery process. Subsequently, I summarize my arguments to the effect that Harvey’s quantitative argument is a «platonic» thought experiment. Thirdly, I present, pace both Pagel and Whitteridge, a new modernist rendering of Harvey, arguing that it is not «quantification», but rather the use of thought experiments which allows us to consider Harvey as an early exponent of modern science. Finally, I investigate to what extent Harvey’s quantitative argument posseses evidential significance intrinsically, thereby qualifying McAllister’s view that evidential significance is only attributed to thought experiments if a scientist or a group of scientists subscribes to certain metaphysical assumptions.