After providing an outline of the process of differentiation between Bulgarian and Macedonian, the author presents an historical overview of the standpoints of the most eminent linguists from before World War II (even before the official codification of Macedonian) to the present, who hold Macedonian to be an individually formed language in relation to Bulgarian. Such differences of systemic character indicate that Macedonian developed differently and differentiated itself continually over the centuries from Bulgarian. In this sense, they are two autochthonous entities, two diasystems, which due to a series of geographical, social, culturo-historical, language contact factors from the very beginning began to differentiate within the Souft Slavic and Balkan context, i.e. to develop from two Old Slavonic variants, that diverged further through the process of Balkanisation which was radical and primarily in Macedonian, i.e. central in contrast to the Bulgarian situation, and ultimately gave rise to two separate literary standards.