The principles of jurisprudence are the methodology of the derivation of Sharīʿa rulings, and in it, the rules and tools for understanding the intent of the Lawgiver are discussed. Hermeneutics is also a methodological device for understanding the meaning of the text and is characterized by three distinct periods: methodical, methodological and philosophical. Methodological hermeneutics considers the meaning of the text as the serious intention of the author. At this point, however, the discussion is not about the tools of understanding the meaning of the text, but about the "theory of understanding the text" which is the source of determining the means of understanding the text providing reasons and justification about their nature. Although the current principles of jurisprudence share semantics with methodological hermeneutics, in the current situation, it includes a discussion of the means of understanding the meaning of the text inasmuch as it lacks an independent discussion about the theory of understanding the text. Meanwhile, this theory exists in the subconscious understanding of jurists and uṣūlis, and its various components have been mentioned in different parts of jurisprudence and its principles. Friedrich Schleiermacher is one of the central hermeneutists of methodological hermeneutics, whose text understanding theory is the main form of this hermeneutic era. In this article, an attempt has been made to extract the hermeneutic theory of Ayatollah Sheikh Muḥammad Ḥusayn Nāʾīnī, who has a theory of understanding due to his creative, coherent and principled mind. Efforts have been made to obtain his theory from his statements as well as to compare it with that of Schleiermacher. The late Nāʾīnī's text understanding theory is based on the central strategy of sticking to the literal meanings of words, and Schleiermacher's text understanding theory is based on the central strategy of reproducing the author's individuality.