His main professional interests were in Greek philosophy – especially Plato, Aristotle, and the pre-Socratic philosophers.
He contributed greatly to building the department; his appointments, included Stuart Hampshire and J. O. Urmson from England and the Canadian philosopher Ian Hacking.
Many important relationships developed and common interests were discovered, at the many conferences and colloquia and courses that Moravcsik sponsored.
These connections among philosophers, linguists, psychologists, computer scientists and others, not only from Stanford but also from research institutes such as SRI and Xerox-PARC, were important in formation of the Center for the Study of Language and Information and the Symbolic Systems Program.
He received Santayana, Guggenheim and ACLS fellowships and was a fellow at the Center for Advanced Study in the Behavioral Sciences and at the Collegium Budapest.
He served as president of the American Philosophical Association, Pacific Division, 1987–88, and of the Society for Ancient Greek Philosophy 2003–04.
A volume of papers by former students and colleagues, presented at a conference honoring him on the occasion of his retirement was published in 2009: Logos and language.