Proceeding from description of the "T-type" (subjective perceptual unit of time) the author demonstrates the linear arrangement of typological groups in human population. This arrangement corresponds to the classical classification of temperaments introduced by Hippocrates. A new psychological meaning is attached to the notion of the "pure type"; an attempt is made to prove that besides the four classical types (sanguine, melancholic, choleric, and phlegmatic) there exists the fifth pure type - "equipoised".