Historians of science – perhaps all historians – use their minds for modelling, making interpretations based on the evidences from the past. Sometimes, in the course of doing history, they are also modelling minds. An example with which I am familiar is the study of the mathematical and logical work of Bernard Bolzano. An evolving website at https://www.bernardbolzano.org is a (rather narrow!) contribution to document and illustrate this ongoing work of ‘modelling minds’.