of the historiography of infinitesimals. After the scorching critique of Berkeley and the triumph of the “great triumvirate” - Weierstrass, Cantor, Dedekind - consequently after the introduction of the Archimedean continuum as the sole possible and analysis based on limits, they were mostly considered, at best, erroneous or, at worst, altogether inconsistent. Nevertheless the group of mathematicians around Mikhail Katz demonstrates in a number of papers that the view of infinitesimals through the lens of the Weierstrassian foundation is misguided. The title of the first paper is typical *Is mathematical history written by the victors?*(Bair et al. 2013) The framework of Robinson’s non-standard analysis is in many cases more helpful in understanding the work of Gregory, Fermat, Leibniz, Euler and Cauchy. (Blaszczyk et al. 2017), (Bair et al. 2017), (Bascelli et al. 2017).

Bolzano’s theory of infinite multitudes
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Bolzano writes that he wants to contribute to the question of what is the infinite in general. He deals with infinite pluralities because

> …if it should be proved that, strictly speaking, there is nothing other than pluralities to which the concept of infinity can be applied in its true meaning, i.e. if it should be proved that infinity is really 