For Prodi, the fundamental semiotic interaction obtains between two molecules. The first selectively "reads' some superficial characteristics of the second, allowing it to establish a link. The fact that a link between two molecules is possible makes the second molecule "meaningful" for the first (and vice versa). "Natural meaning" thus arises. At the beginning of semiosis, there is a selective material operation, wherein a certain material configuration is "preferred" to another. All the other forms of semiosis derive from this fundamental operation. Prodi's theoretical proposal, then, does not presuppose the existence of any intentional process. Semiosis, Prodi argues, does not need a subject or any psychological intentionality. Consequently, semiosic processes are completely natural and are not an exclusive prerogative of human beings.