The scientific endeavor has always been determined by collaborations and competitions. Together, they are often understood as the two antagonistic extremes of the possible interactions between scholars and scientists.

Whereas collaboration and cooperation are seen as an essential component with an highly positive outcome for the advancement of science, competition—which can end in confrontations, quarrels and controversies—is mostly labeled as the dark side of science in the making. It seems to be reminding us that scientists are humans like any others, fighting for their reputation, arguing for their truth, being blinded by prejudices and partiality.

By analyzing Leonhard Euler’s (1707-1783) wide network of friends and foes, disciples and detractors, intermediates and go-betweens, I intend to gain a better understanding of both categories and to re-evaluate some preconceived notions. I shall argue that forms of collaborations and confrontations are much more entangled that what many previous studies let think—up to the point that it is sometimes difficult to distinguish between both of them. Far from being simply antagonistic, they cover a broad range of various communication and negotiation forms which must be catalogued.

For that purpose, my doctoral dissertation will first explores practices of collaboration and confrontation as well as their meaning and place in the former scientific community, the so-called Republic of Letters. I will then present some significant case studies. At the end, we will hopefully see that controversies and quarrels are just as constitutive of science as successful cooperations—not only during the exceptional period of a paradigmatic change but in the day-to-day scientific activity. Furthermore we should see that collaborations and confrontations are processes which take place simultaneously and not successively as suggested by the established model of normal vs. revolutionary science.