It is a classical work outlining principles of socionics. It describes 16 types of informational metabolism (TIM) which form together the Socion. The latter represents generalization of C.G.Jung’s psychological typology. Nature of erotic senses is studied. The work demonstrates that each TIM has its own complementary (dual) type, the best compatible partner in private life (family and friendship), at work etc., which protects the most vulnerable traits of his partner by his strong traits.