 By the end of the 1970s, a group of analytic philosophers had distinguished themselves: Enrique Villanueva (b. 1938), José Antonio Robles (1938–2014), Margarita Valdés (b. 1941), Hugo Margáin (1942–1978), and Olbeth Hansberg (b. 1943), author of La diversidad de las emociones (b. 1996). In the 1980s, more analytic philosophers joined the Institute of Philosophical research, among them: Raúl Orayen (1942–2003), who wrote Lógica, significado y ontología (1989); Ulises Moulines (b. 1946), a structuralist philosopher of science; Mark Platts (b. 1947), author of Ways of Meaning (1979); León Olivé (1950–2017), who wrote several books of philosophy of science and culture; and Adolfo García de la Sienra (b. 1951), a theologian and philosopher of economics.