For human beings the world is conceptually organized, principally by language, their most important tool for dealing with life. Observations on the development of language reveal that it is a far more complicated process than formerly supposed. It is no longer so tenable that the acquisition of language arises solely from the human being's powerful instinct to imitate. Among the important factors in language development which are discussed are prolonged dependency, playful contact with objects available to senses and motor apparatus, narcissistic pleasure in self-created stimuli, awareness of the similarity between the self and others, pleasure from vocal functioning, and the greater importance of the distance receptors for the human infant.