In didactical or 'Ā dā b' treatises on calligraphy, one can find spiritual/ethical dimensions in a variety of subjects the analysis of which could lead to a clearer understanding of the structure and uses of these texts. With this end aimed at, the present article has studied thirteen Persian treatises (belonging to the 14-18th centuries) addressing their spiritual/ ethical aspects in two categories of spiritual/ethical “ attitudes” and “ principles” with respect to their two descriptive and prescriptive components. Thus, spiritual attitudes, including quotations, references, sacred mythical and mystical meanings, have been discussed and so have spiritual/ethical principles in two categories of general and special principles of calligraphy. According to this study, the spiritual/ethical attitudes in the treatises referred to above follow, to some extent, a far-reaching and formulated tradition. Conversely, the spiritual/ethical principles enjoy less frequency and extensiveness and have less coherence. However, there are to be seen certain blending and contradictions in these principles, which sometimes stem from the mystical tendencies of the authors and, sometimes, aim at guild distinction. At the same time, the state of spiritual aspects in calligraphy handbooks have no direct correlation with a historical timeline and varies depending on individual authors.