Reima Pietilä had also been active in the activities of the Museum of Finnish Architecture as well as publishing theoretical articles in "Le Carré Bleu" and "Arkkitehti". Pietilä even attended a meeting of the Team X group of architects, held in 1972 at Cornell University in the US, who were very much concerned with questions of structuralism in architecture, that is emphasising the elements of culture, somewhat in reaction to the universalising tendencies of modernism, especially as originally promoted by Team X's instigators, the older generation of CIAM. Pietilä took a diametric viewpoint to that of the rationalist school, and though the works (designed in partnership with his wife Raili Pietilä) had much of the organic idiosyncrasies of Aalto, they were far more abstract and nebulous. In arguing that nature is the apotheosis of plasticity, he demanded a morphological analysis of architectural products, considering Euclidean geometry as an inadequate instrument of analysis. His first major work, the Finnish Pavilion at the 1958 Brussels Expo did in fact take a modular approach akin to the theories of Blomstedt; however, the wooden rectangular box-like units as a whole gave a foretaste of Pietilä's later surfaces based entirely on free form; the most notable of these organic works being Kaleva Church, Tampere (1959–1966), Dipoli student assembly building, Espoo (1961–66), Metso Library, Tampere (1978–1986) and culminating in his final work, the Official Residence of the President of Finland, Mäntyniemi, Helsinki (1983–1993). All these buildings had been the result of open architectural competitions.