ENAt this article the author is considered the conception of ecclesiastical unity at works of Piotr Skarga, polish religious thinker (1536 – 1612). The conception had purposed to justify necessity of the Catholic and the Orthodox Churches under the supremacy of the Pope. Unlike other Catholic polemists, which noted the dogmatic distinction between the Churces, Skarga accentuated on positive consequences from acceptance Pope's power by Orthodoxes. 149.