Full context:   The sign does not function as its own goal, but its purpose lies in its role as a signification (res significans, DDC 3.9.13). God gave signs as a means to reveal himself; Christians need to exercise hermeneutical principles in order to understand that divine revelation. Even if the Scriptural text is obscure, it has meaningful benefits. For the obscure text prevents us from falling into pride, triggers our intelligence (DDC 2.6.7), tempers our faith in the history of revelation (DDC 3.8.12), and refines our mind to be suitable to the holy mysteries (DDC 4.8.22). When interpreting signs, the literal meaning should first be sought, and then the figurative meaning (DDC 3.10.14-3.23.33). Augustine suggests the hermeneutical principle that the obscure Scriptural verse is interpreted with the help of plain and simple verses, which formed the doctrine of "scriptura scripturae interpres" (Scripture is the Interpreter of Scripture) in the Reformation Era. Moreover, he introduces the seven rules of Tyconius the Donatist to interpret the obscure meaning of the Bible, which demonstrates his understanding that all truth belongs to God (DDC 3.3.42-3.37.56). In order to apply Augustine's hermeneutics of the sign appropriately in modern times, every division of theology must be involved and interdisciplinary approaches must be taken.