Balint 'took an early interest in the mother-infant relationship...a key paper on "Primary Object-Love" dates from 1937'. Thereafter, developing an idea of John Rickman, he argued that 'mental function is quite different, and needs to be described differently, in three-person and two-person relationships, and different in creative activity alone'. Lacan wrote (almost approvingly) that 'Michael Balint has analysed in a thoroughly penetrating way the intricate interaction of theory and technique in the genesis of a new conception of analysis... the catchphrase, borrowed from Rickman, of a "two-body psychology"'. On that basis, Balint thereafter explored the idea of what he called '"the basic fault": this was that there was often the experience in the early two-person relationship that something was wrong or missing, and this carried over into the Oedipal period (age 2–5)'.