The emotions impact every single process in an individual’s life. An analysis of the scientific works selected by a Google search based on the terms ‘emotions, Vygostky, Leontiev’ shows that the complexity of the topic is multiplied by the complexity, mixture and fragmentary nature of the approaches applied to the investigation of the emotions. The aim of this work is to revisit the works of Vygotsky and Leontiev relating to the emotions underpinning the identification of notions, features and functions of the emotions. A novel research methodology, the development of the system of external and internal perspectives, was implemented. The investigation into the emotions was based on the theories of Vygotsky and Leontiev: activity theory, law of development, psychological system, word meaning, concept formation, and the unity of language. The theoretical analysis resulted in the definition of notions, features and functions of the emotions. The limitations of the research were identified. Further research directions are proposed.