The perception of perception is the pre-social requirement of interaction. Communication demands the mutual perception of perception: the participants perceive that they themselves are perceived. If they perceive that they are perceived, and that their own perception is also perceived, the participants in communication can observe that their Behavior is understood as Information. This makes Communication unavoidable, since even non-communication is observed as communication, i.e. as rejection of communication. Therefore, it is impossible not to communicate in interaction systems.