  Zermelo's opposition had a quite different background. When he put forward the recurrence objection in 1896, he was an assistant to Planck in Berlin. And like his mentor, he did not favor the mechanical underpinning of thermal phenomena. Yet his 1896 paper (Zermelo 1896a) is by no means hostile.  It presents a careful logical argument that leads him to a dilemma: thermodynamics with its Second Law on the one hand and gas theory (in the form as Zermelo understood it) on the other cannot both be literally true.  By contrast, it is Boltzmann's (1896b) reaction to Zermelo, drenched in sarcasm and bitterness which (if anything) may have led to hostile feelings between these two authors. In any case, the tone of Zermelo's (1896b) is considerably sharper.  Still, Zermelo maintained a keen, yet critical, interest in gas theory and statistical physics, and subsequently played an important role in making Gibbs' work known in Germany.