 In thinking about the scope of the logic of relations, the question arises: Why did Pierce feel the need for another form of representation different from the 1885 notation? “I must clearly show what a relation is” (1897a [CP 3.456]). The clear understanding of “relations”, Peirce believes, is a guide for his excursion into different forms of logical systems. Here we would like to draw reader’s attention to Peirce’s well-known paper “How To Make Our Ideas Clear ” (1878), where three sections are devoted to the three grades of meaning (see the entry on  Peirce’s theory of signs).