un critère d’équivalence par l’intermédiaire d’une bijection. Ce conflit profond, qui éclate presque dans chaque section des *Paradoxes de l’infini*, l’empêche de construire une arithmétique de l’infini qui soit cohérente. (Šebestík 1992, p. 464).

Jan Berg, an expert on Bolzano and publisher of his works, found a passage in one of Bolzano’s late letters to Robert Zimmermann which Berg interprets, in an effort to save Bolzano’s reputation, as Bolzano changing his opinion and accepting the existence of one-to-one correspondence as a sufficient criterion for the equality of sets.

> Hence, it seems that in the end Bolzano confined the doctrine that the whole is greater than its part to the finite case and accepted isomorphism as a sufficient condition for the identity of cardinalities of infinite sets. (Mancosu 2009, p. 625).

Both Rusnock (Rusnock (2000), pp. 194 - 196.) and Mancosu examine this passage and consider Berg’s interpretation to be groundless. Mancosu says, tongue-in-cheek

> Thus, Bolzano saved his mathematical soul in extremis and joined the rank of the blessed Cantorians by repudiating his previous sins. ... I must observe that the literature of infinity is replete with such ‘Whig’ history. (Mancosu 2009, p. 626).

The situation is similar that 