For the very first time, Russian readers are offered the translation of one of the most rarely published (in the Arab world) and practically unknown (everywhere else) works of Abū Ḥayyān al-Tawḥīdi (930-1023), “[An Epistle] on Penmanship (Arabic Calligraphy)” (982). As one of those who popularized knowledge, an encyclopedist, an unrivaled master of style and a Mu’tazilite scholar Al-Tawḥīdi, using Adab literature, shares all that was known to him about this form of Arabic literature up until its compilation. In an elegant manner, he reveals its secrets, gives us valuable recommendations, and conveys the universal admiration of the famous sages, writers, scribes, and court secretaries of that time. This epistle is considered the first professional work of this art form in the Arab tradition. At the time this piece was written, the seven “canonical” types of Arabic writing were not yet developed in the form and with the names, we are familiar with now. Nevertheless, this is what makes this treatise even more precious in raising the Adībs as well as the well-educated urban youths of those days. It sheds light on the history of their creation at the initial and, perhaps, the most crucial stage. The theoretical basis and the most important rules of proportional writing were formed back then and remain unshakable to this day.