Segnaliamo il ricordo di Pietro Omodeo, a firma di Elena Gagliasso e Saverio Forestiero, pubblicato sulla rivista Physis.

At 104 years old, on January 20, 2024, Pietro Omodeo concluded his life. Zoologist, cytologist, historian of natural sciences, he was, with Giuseppe Montalenti (1904-1996), one of the first great biologists of the Italian 20th century. In the postwar period he opened our culture to evolutionary thought and with his historical-critical research he laid the seeds of what would later also become a distinctive historical philosophy of biology.

In a country, in the mid-20th century, still steeped in culture inspired by Benedetto Croce’s idealism, and later torn between scientism and irrationalism, Omodeo – a materialist, naturalist, and attentive to the early dynamics between eco-evolution and cybernetics – was both a beacon and a pioneer.

Born in Cefalù, in the province of Palermo, on Sept. 27, 1919, he spent his early childhood in Catania and then in Naples, where his father Adolfo (1889-1946), a progressive liberal of the Partito d’Azione, a leading historian of Antiquity and the Risorgimento, and Minister of Education after the Liberation, was a university professor.

The young Omodeo, who precociously entered the Natural Sciences course at the Scuola Normale Superiore in Pisa, later studied with the likes of Umberto D’Ancona, Giuseppe Colosi, Alberto Chiarugi and Giuseppe Caraci. At the age of 19, in 1938, he enlisted in Natural Sciences and graduated on June 11, 1940, the day after Italy entered WWII. He will then be with the Italian Army in Libya for six years, fight in the Battle of El Alamein and later be a prisoner in Egypt.

Only after the war, in the laboratories of the Zoological Station in Naples, did he begin his career as an earthworm biologist and embryologist. Meanwhile, in 1947, he married pianist Miriam Donadoni; she would be his lifelong companion and together they would raise five children.

His educational background was enriched in 1949 by world-renowned biologist Emanuele Padoa (1905-1980), with whom he would work in Siena and from whom he inherited the teaching of Zoology, deepening his study of oligochaete worms, their morphology, cytology, zoogeography and systematics.

Later, during the 18 years in which he taught in Padua, he wrote treatise Biology, a masterly and still significant work in which basic biology topics for the first time in Italy are integrated and originally interpreted with a systemic and cybernetic approach; a familiar perspective to him already since the 1950s, thanks to his acquaintance with Norbert Wiener, Ludwig von Bertalanffy, Ross Ashby, and then thanks to the intense frequentation of Italian cyberneticians and biophysicists, such as Antonio Borsellino, Eduardo Caianiello, Vittorio Somenzi. Well in advance Omodeo grasps what will become one of the pillars in the study of biology: the living is held together not only by physical forces (e.g., cohesive forces between cells), and by flows of matter and energy, but also by flows of codified and regulated information. With the emergence of the “living state of matter” – an expression of a close friend of his, the biologist Marcello Buiatti – we move, so to speak, from forces to codes. This idea was already expressed – though still as an embryo – in his inaugural lecture on Cybernetics in Zoology that he gave at the opening of the 1966-67 academic year in Padua, and which would be fully developed theoretically in his 1996 definition of the living. In the entry Homeostasis for the fourth volume of Treccani’s Encyclopedia of the Twentieth Century – a masterly essay appeared in 1979 – he comprehensively analyzed its critical issues such as the phenomenon of regulation, a pillar of physiological adaptation and a defining moment in the control of morphogenesis.

The 1970s-1980s are particularly important and fruitful, because the biologist is also morphing into a historian and theorist of biology. Between 1967 and 1980 Omodeo edits (for the Feltrinelli publishing house) Charles Darwin’s Journey of a Naturalist Around the World. He later translates and introduces Darwin’s Letters (1831-1836) and Autobiography, and writes the introductory historical-critical review for the translation of the 1859 unabridged edition of On the Origin of Species, including the changes introduced in the 1872 edition. In this text, he analyses the different versions of evolutionism in eighteenth- and nineteenth-century, up to Darwin, reconstructing how the idea of natural selection matured in the mind of the English naturalist. Finally, for the first time in Italy, due prominence is given to the evolutionism of the naturalist and zoogeographer Alfred Russel Wallace.

But in addition to Darwin, Omodeo’s historical passions include Jean-Baptiste Lamarck, the great French naturalist and theorist transformism. Omodeo landed him in Italy in 1969 by translating and editing an anthology of Lamarck’s work, with a long introduction and detailed bio-bibliographical notes.

Omodeo’s first interest in Lamarck dates to his postwar period in Naples, when he studied the zoologist Giosuè Sangiovanni, a Lamarck’s student in Paris. In the Sangiovanni archival collection, Omodeo finds many uninventoried papers, including the correspondence with Lamarck. In 1946 he went to Paris and in a couple of months he published Lamarck’s writings found in Naples. The study of those manuscripts shows Lamarck’s socio-evolutionary aspect, and Omodeo would emphasize this character in a 1949 essay in the Bulletin of Zoology (16th volume).

His arrival in 1984 at the University of Tor Vergata in Rome is preceded by one of his calling card, the new book Creazionismo ed Evoluzionismo. The dispute over creation, the origin of man and the history of the Earth is here documented and interpreted not only as a bitter cultural diatribe against the authority of the Bible, but also as a dispute with technical and economic implications. Paleontologists and geologists, naturalists and philosophers, clergymen and entomologists, are all involved, from Francesco Redi to Charles Darwin, in a controversy over religious orthodoxy and scientific progress, academic power and the structure of society, so that in Omodeo C.P. Snow’s ‘two cultures’ face each other in a tight, lively and creative dialogue.

Alongside these theoretical and historical works, he always continued to study his earthworms, with exploratory collecting missions in the Maghreb and Turkey, relaunched and edited the Bulletin of Zoology, and published scientific and field papers in the most important journals.

The conversation and the teaching of this professor, ‘anthropologically’ different from all others, fascinated students and colleagues: on May 31, 1989 at his last lecture, the Aula Magna of the Faculty of Science at Tor Vergata was packed with scientists, humanities scholars and doctors. Omodeo dwells on one of his favourite themes: the relationship between physics and biology, a biology ‘beyond molecules,’ in defense of his discipline’s autonomy as a historical science. This masterful lecture, ‘The Two Sisters,’ will become one of the final essays in the volume Biologia con rabbia e con amore (Biology with anger and with love), which collects writings and essays that have appeared in prestigious journals, or as forewords, introductions, and commentaries to several authors including Rorvik, von Bertalanffy, Riedl, Eccles, Pierantoni, Watson, Barbieri, Lewontin, Rose, Chargaff, and Monroy.

In 2000, with Gli abissi del tempo (The Abysses of Time) his encyclopedic culture is at work again, combining the intellectual history, the history of biology, and the history of sensist philosophy to analyze how the duration of deep time was conceived. We find the interpretation of nature in Denis Diderot, early studies on the development of the mind, the notion of order in biology, the relations between philosophy and science in Linnaeus, Darwin, Lamarck, Condillac, up to Schrödinger. A year goes by, and Alle origini delle scienze naturali (The Origins of Natural Sciences) is published, an exquisite work nourished by his fabulous private library of rarities in the history of science: a survey of the dawn of the experimental method and of inductive practices in the natural sciences. Then, about ten years later, in Evoluzione della cellula (Evolution of the Cell) he reconstructs, with a bibliographical apparatus covering over half a century of research, the history of cell evolution: from the first bacterial-type cell to the eukaryotic cell. Omodeo collects, sorts, interprets and links together an enormous and heterogeneous amount of data from the most diverse fields of inquiry, dealing with events distributed over hard-to-conceive time spans of billions and billions of years. This work displays not only Omodeo’s constant ability to renew itself, but also his inexhaustible interest in the great problems of biology.

His latest extraordinary feat, on the brink of one hundred years of age, is the book on Amerigo Vespucci e l’annuncio del Nuovo Mondo (Amerigo Vespucci and the Announcement of the New World). A long research, a careful historical reconstruction of Vespucci’s both scientific and navigational activities that documents step by step the reliability of the great Florentine navigator’s manuscripts.

If we go back to the years immediately following his retirement, we still find him in Rome. Here, he continues to hold seminars, completes research, and for several years he mingles in the philosophical environment of the University la Sapienza. Precisely at Sapienza, in the Department of Philosophy, he was among the founders of the “Philosophies of Biology” group in 1993, the first nucleus of the later Inter-University Center for Epistemology and History of the Life Sciences ResViva. There, biologists, naturalists, philosophers, epistemologists, historians of the life sciences, physiologists, neurophysiologists, animated by the curiosity, by the involvement and the reciprocal contamination among different people, discussed in a periodical and informal seminar, a context free from academic status.
Omodeo, together with other founders such as Aldo Fasolo, Marcello Buiatti, Vittorio Somenzi, Silvano Tagliagambe, Guido Modiano, Umberto di Porzio, including the Authors and other intellectuals, studied the texts suggested within the group, not unlike a serious doctoral student would have done. He connected the field experience as a zoologist and as a historian of life sciences with the transversality of other styles of reasoning that were exchanged within the group. For Omodeo, a naturalist and possibly the first historian and theorist of evolutionism in Italy, the essence of intellectual, creative, and relational productivity lay in the long-term investment of mental engagement. With him, we learned that ‘waste’ – the un-academic canon of ‘waste’ as something not aimed immediately at a ‘product’ – is instead redundancy: a function as consonant as ever with what biological and mental evolution actually operates at every level of the living world.

In short Omodeo could – style-wise – almost be called a new Darwin, not least because of his way of being as well as his way of reasoning: that clarity in the pursuit of phenomena and processes, from earthworms to cells, from cybernetics to naturalism in the field, and that immense encyclopedic culture that tackled new studies even late in life.

A quarter-century ago, introducing his Biologia con rabbia e con amore, he wrote (with an eye to the future): “love for the boundless and beautiful nature and anger at the irreparable havoc being wrought upon it, love for biology and anger at the distortions and distorted uses of it, anger and love to be cultivated in order to dedicate this book to the new generations who inherit a planet devastated by an unconscionable policy of plunder and a murky and threatening future.”

A very long, passionate life, when well spent, with intelligence and dedication, contains many forms, many succeeding inner landscapes, almost a kaleidoscope of many lives, and nurtures countless human relationships. Thus, the rich and complex person of Pietro Omodeo, with his strong ethical drive and concrete political commitment, never inhabited the ivory tower of the Academy. He was not only a great researcher, a professor much loved by students, a leading evolutionist, a historian and theorist of biology, but first and foremost a free man, a gentleman, honest and generous. And unforgettable.


  • Biologia (UTET, 1977)
  • Creazionismo ed Evoluzionismo (Laterza, 1984; Ed. Bibliografica, 2022)
  • Biologia con rabbia e con amore (UniTor, 1989; a cura di Emilia Rota, 2020)
  • Gli abissi del tempo (Aracne, 2000, 2020)
  • Alle origini delle scienze naturali (Rubettino, 2001)
  • Evoluzione della cellula (ETS, 2010)
  • Amerigo Vespucci e l’annuncio del Nuovo Mondo (Artemide, 2017)
  • Amerigo Vespucci: the historical context of his explorations and scientific contribution (ed. by Pietro Daniel Omodeo, Ca’ Foscari, 2020)
  • Amerigo Vespucci, il contributo alla scoperta del Nuovo Mondo (Robin, 2021).


  • Lamarck, Opere (UTET, 1969)
  • Darwin, L’Origine delle specie (Newton Compton, 1974).
In ricordo di Pietro Omodeo

Potrebbe anche interessarti