There is absolutely nothing divine about the Shariah and in no way can it possibly be considered fixed and infallible. The argument that the Shariah derives its divine nature from its first and primary source, the Quran, falls flat when one recognizes that the Quran, unlike the Torah, is not a book of laws. The Quran is God's direct self-revelation to humanity. Certainly, it contains the moral framework for living a holy and righteous life as a Muslim. But it was never meant to function as a legal code, which is precisely why scholars had to rely so heavily on extra-Quranic sources like ijma (consensus), qiyas (analogy), istislah (which refers to the common good of the people), and ijtihad (independent juristic reasoning)--all of them, by definition, reliant on human judgment and historical context--in order to construct the Shariah in the first place. To say the Shariah is divine because the Quran is divine is akin to arguing that water and wine are the same, since water is a primary ingredient in wine.