Solomonick's general theory, the six types of sign-systems are arranged in a way that reflects both the order in which they appeared in human phylogenetic development (the development of the species as a whole, over time) and the order in which they appear ontogenetically in the understanding of each human being as they grow and develop. At the inception of the human race, the first signs humans encountered and accepted as such, were natural signs. Every natural phenomenon served them as a sign; smoke was a sign of burning, darkness was a sign of approaching night, etc. As people grew accustomed to these kinds of natural signs, they began to invent artificial signs as well. First, they invented signs that resembled the things they denoted – images of their prototypes. Then they started to think up signs that were more and more remote from the things they signified. Thus, sign-systems built upon words appeared, followed later by sign-systems built on graphemes, and, finally, sign-systems whose signs are entirely arbitrary – mathematical signs and other symbols. The theory of general semiotics arranges the types of sign-systems in a hierarchy that reflects this gradual development. Each higher level in the hierarchy represents basic signs of more abstract character – more remote from the things they denote – than the basic signs of the level below it. This hierarchy is illustrated in the diagram above. In the course of human development, each type of signs could only come into existence with the support of its predecessors. Furthermore, once it came into existence, each type of signs affected the further development of all previous types of signs. The various sign-systems that have developed at each stage in human history, and their interdependence, have shaped the science and culture of every generation since the dawn of mankind. The collection of signs and sign-systems that surround us at any given moment constitute the semiotic reality we use in our everyday life, in our scientific investigations, and in our cultural activities. In the course of semiotic development, people gradually improved their minds and acquired new qualities. Mastering natural signs helped them to cope with pressing everyday problems. Iconic sign-systems developed the imagination and allowed the arts to be pursued. Languages have provided the ability to logically discuss any problem that arises; notational systems created interpersonal communication and ensured the preservation of the acquired knowledge for posterity; formalized