Professor César Ades passed away on 14th December 2012, after being hit by a car near his home in São Paulo, Brazil. He leaves an immense void in his family, friends, colleagues and students. We will always remember him, not only for his remarkable achievements as ethologist, researcher and professor, but also — and maybe mainly — for his enthusiasm for all types of manifestations of life. His warm personality, along with his accurate view of the processes and motivations of behaviour, has left an indelible mark on all persons around him. In his memory, a brief overview of his life and achievements follows.

César Ades was born in 1943 as an Egyptian, but moved to Brazil and naturalized as a Brazilian when he was 15. He early expressed a strong interest in behaviour: at the age of 13, he developed his first "experiment", in a garden in Alexandria, by introducing insects and leaves in the web of a spider and observing the animal's reaction. This interest would lead him, later on, to study further the processes involved in memory, web building, foraging, instinct and learning in spiders. It was this exploratory nature which, along with his knowledge, led him to his current list of achievements: a parade of animals and problems, each one receiving the same endeavour put in his first spider-experiment. Since graduation, he started writing papers and, as early as 1965, he published his first experimental results. Having graduated in this very year, César right away started teaching at the University of São Paulo, where he had been working until his departure. He developed relevant research on several areas of ethology: his research projects were really varied, covering areas as diverse as conditioning, memory, learning, exploration and foraging behaviour, responses to social isolation, vocal behaviour, social organization, mother-infant recognition, courtship behaviour, domestication, welfare, human-animal relationship and animal communication. His studies covered the impressive amount of 60 species! He was the author of over 100 publications and was actively sought out to present his research results and recommendations at national and international venues. His most recent production was an anthological paper on dog comprehension of verbal requests, published one month before his departure.

Besides his contributions as a researcher, César was also influential in the establishment and progress of the conceptual basis of ethology and psychology. In the sixties, he introduced the discussion about the study of motivation in Brazil, having influenced significantly the following generations of theorists and researchers. In 1978, he proposed a discussion about the epistemological crisis in psychology; later on, he advocated the need for theoretical and cognitive concepts and pioneered, proposing the adoption of a psycho-ethological perspective in psychology. César Ades contributed significantly to the recognition and consolidation of ethology in Brazil and was one of the founders of the Brazilian Ethological Society.

César served in a variety of professional capacities, among them the president of the Brazilian Ethological Society from 1994 to 1998, the vice-director of the Institute of Psychology (University of São Paulo) from 1998 to 2000 and director of this Institute from 2000 to 2004, period in which he dedicated to create the Committees for Ethics in Human and Animal Research. From 2008 to 2012, he was the director of the Institute of Advanced Studies, from the University of São Paulo. Since 1999, he had been the editor of the Brazilian Journal of Ethology (Revista de Etologia). César occupied one position in the Academia Paulista de Psicologia, a prestigious academy that brings together, forever, forty Brazilian professionals of great significance in teaching, research or professional practice of psychology, residing in the State of São Paulo.

His distinguished profile as a professor usually raised the interest of students. As he was always interested in and attentive to new aspects of behaviour, he encouraged his students to carefully record and study several different types of behaviour. César believed undergraduates were able to contribute new ideas in the research, since they had "originality of a free thought, not tied to the knowledge of the manuals". As an outcome of this view, César Ades was the fruitful builder of active and curious researchers, today turned into admirers and working as professors and researchers in several different universities throughout the country. He is survived by his daughters Lia Ades Gabbay and Tatiana Ades.