and developed the classical and Hellenistic theories of signs. Among the mainstream in the theories of signs, i.e., that of Aristotle and that of Stoics, the former theory filtered into the works of Cicero (106-43 BC, De inventione rhetorica 1.30.47-48) and Quintilian (circa 35–100, Institutio Oratoria 5.9.9-10), which regarded the sign as an instrument of inference. In his commentary on Aristotle's De Interpretatione, Ammonius said, "according to the division of the philosopher Theophrastus, the relation of speech is twofold, first in regard to the audience, to which speech signifies something, and secondly in regard to the things about which the speaker intends to persuade the audience." If we match DDC with this division, the first part belongs to DDC Book IV and the second part to DDC Books I-III. Augustine, although influenced by these theories, advanced his own theological theory of signs, with whose help one can infer the mind of God from the events and words of Scripture. Books II and III of DDC enumerate all kinds of signs and explain how to interpret them. Signs are divided into natural (naturalia) and conventional (data); the latter is divided into animal (bestiae) and human (homines); the latter is divided into non-words (cetera) and words (verba); the latter is divided into spoken words (voces) and written words (litterae); the latter is divided into unknown signs (signa ignota) and ambiguous signs (signa ambigua); both the former and the latter are divided respectively into particular signs (signa propria) and figurative signs (signa translata), among which the unknown figurative signs belong to the pagans. In addition to exegetical knowledge (Quintilian, Institutio Oratoria 1.4.1-3 and 1.8.1-21) which follows the order of reading (lectio), textual criticism (emendatio), explanation (enarratio), and judgment (iudicium), one needs to know the original language (Hebrew and Greek) and broad background information on Scripture (DDC 2.9.14-2.40.60). Augustine's understanding of signs includes several hermeneutical presuppositions as important factors. First, the interpreter should proceed with humility, because only a humble person can grasp the truth of Scripture (DDC 2.41.62). Second, the interpreter must have a spirit of active inquiry and should not hesitate to learn and use pagan education for the purpose of leading to Christian learning, because all truth is God's truth (DDC 2.40.60-2.42.63). Third, the heart of interpreter should be founded, rooted, and built up in love which is the final goal of the entire Scriptures (DDC 2.42.63). The sign does not