Born in Buenos Aires, Argentina, in 1935, polymath philosopher of science Eliseo A. Fernández worked as a physics professor, statistician, and as a reference librarian at the prestigious Linda Hall Library for Science, Engineering and Technology from 1968 until his death in 2017 at age 82. All of his adult life was devoted to the examination of the organizing concepts structuring scientific understanding, and in the last decade of a long and distinguished scholarly career, he found his way towards, and into, the community of biosemiotics scholars at The Seventh International Gatherings in Biosemiotics in 2007, with a talk entitled “Signs, instruments and self-reference in biosemiotics: The convergence of Aristotelian and Kantian intuitions” (Fernández 2008). That talk, like much of Eliseo’s work (see especially Fernández 1993, 2010, 2011, and 2012) was itself concerned with the historical “trajectories” of scientific understanding, but it is his own trajectory through the conventional history and philosophy of science literature and complexity theory, to the developmental semiotics of Charles Sanders Peirce, and from there to biosemiotics, that will be the subject of the present talk. Taking up Peirce’s challenge that “the problem of how genuine triadic relationships first arose in the world is a better, because more definite, formulation of the problem of how life came about” (CP 6.322), Eliseo was able to bring both a physicist’s rigor and a philosopher’s sense of nuance to his consideration of the evolution of sign processes in and by life processes, and his later work in particular (see especially Fernández 2014, 2015a, 2015b, 2016, 2017) was explicitly concerned with the developmental and evolutionary trajectories enabled by Peircean habituation, biosemiotic scaffolding, and generalization as both a semiotic and an ontological phenomenon. In this brief talk, I will outline some of Eliseo’s most original and important contribution to biosemiotics, and do my best to honor the memory of our dear friend and colleague in his native Buenos Aires. References: Fernández, E. (1993). From Peirce to Bohr: Theorematic reasoning and idealization in physics. In E.C. Moore (Ed.), Charles S. Peirce and the Philosophy of Science: Papers from the Harvard Sesquicentennial Congress Tuscaloosa: University of Alabama Press, pp. 233–245. Fernández, E. (2010). Taking the relational turn: biosemiotics and some new trends in biology. Biosemiotics 3 (2), 147-156. Fernández, E. (2011). How the Tree of Life became a Tangled Web: A glimpse at the history of a powerful metaphor. 54th annual meeting of the Midwest Junto for the History of Science, Lincoln, Nebraska, April 1–3, 2011. Available at: http://www.lindahall.org/services/reference/papers/fernandez/Tree_of_life.pdf. Fernández, E. (2012). Symmetry breaks out—a fundamental concept jumps over disciplinary barriers. Midwest Junto for the History of Science. University of Missouri of Science and Technology, Rolla, MO, U.S.A. Fifty-fifth annual meeting, March 23–25, 2012. Fernández, E. (2014). Peircean habits, broken symmetries, and biosemiotics. In V. Romanini and E. Fernández (Eds). Peirce and Biosemiotics. Dordrecht: Springer, pp, 79-94. Fernandez, E. (2015a). Signs, dispositions, and semiotic scaffolding. Progress in Biophysics and Molecular Biology, 119(3), 602–606. Fernández, E. (2015b). Evolution of signs, organisms and artifacts as phases of concrete generalization. Biosemiotics, 8(1), 91–102. Fernández, E. (2016). Synergy of Energy and Semiosis: Cooperation Climbs the Tree of Life. Biosemiotics 9 (3), 383-39 Fernández, E. (2017). Semiosis and emergence: The place of biosemiotics in an evolutionary conception of nature. Chinese Semiotic Studies13(4).