All perfect praise be to Allah, the Lord of The Worlds, and may His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
If both ends of the line are defined, then moderation is defined as well. From the perspective of Islamic Sharia, moderation isn`t an arithmetic concept; rather, it is a special, linguistic, Islamic concept that means: the truth and the best.
This is indicated in the verse: "Thus We have appointed you a middle nation" {Al-Baqarah/143}, i.e. the best and most trustworthy; as indicated by the complement of the above verse: "that ye may be witnesses against mankind."
Thus, the only acceptable testimony is that of the trustworthy, and this is reflected in the words of Allah: "Ye are the best community that hath been raised up for mankind" {Al-Imran/110}. This same meaning is reiterated by the Words of Allah: "Say: (It is) the truth from the Lord of you (all)" {Al-Kahf/29}; therefore, the truth is what Sharia has come with. And Allah Knows Best.