There is given a short review of the most important biographical information about Abū Ḥayyān al-Tawḥīdi (d. ca. 1023), an outstanding representative of the Adab literature. Amongst his creative heritage it is emphasized the importance of the «Epistle (on Penmanship)». The conclusion is made that Adab style served in the best way the author’s intention. He was the first one who succeeded to exhaustively summarize the primary (defining) stage of the Arabic script formation, to clearly formulate the technique for preparing the qalam . The “Epistle” is written in a simple manner, though it is not devoid of traditional elegance and eclecticism. Anticipating further development of the multiple types of proportional script referring to the existent schools, al-Tawḥīdi formulates common additional principles (apart from proportions), that, according to him, would constitute their aesthetics in future. In the second part of the “Epistle” there are given classic sayings and teachings, that became commonplace, regarding this type of art. Al-Tawḥīdi goes beyond his contemporaries and authors of the inner tradition. He gives the full scope of then existing knowledge regarding the discourse object. These data can be divided into rubrics depending on the subject and genre. In many of them we can trace the author's desire to zealously protect the Arab cultural heritage. It is concluded that al-Tawḥīdi strived to take out and convey further the main information, rules and techniques from the previous era of styles formation, so that they would not be lost or significantly changed. The writing contains numerous terms related to the preparation of tools and the process of script itself, which may again become relevant in the modern science of calligraphy.