In the present paper it is elucidated that the oldest stage of the development of thought doesn't acknowledge time relationships. At first there must have been the eternal tense forms and then people must have singled out the Present Tense from the continuous chain of time, which must have been followed by the comprehension of the Past Tense. The Future Tense is the most recent formation. The category of tense was formed only then when there appeared the two tenses – Present and Past, and when they apposed each other.