Key Themes: Scriptural Critique, Islamic Sects, and the Dhahiri Standard of Evidence

The most intellectually striking sections of Al-Fisal are those dealing with Jewish and Christian scriptures. Ibn Hazm's critique is grounded in the Islamic theological claim that the original Torah and Gospel were genuine divine revelations but that the texts currently in Jewish and Christian hands have been corrupted (tahrif). He goes beyond simply asserting this theological claim, however, to argue it from textual evidence — cataloguing specific passages in the Bible that he considers historically implausible, internally contradictory, or theologically unworthy of divine authorship.

His biblical criticism includes: arguments about the historical impossibility of certain events as described, apparent contradictions between passages in different books of the Bible, passages that attribute morally problematic actions to prophets, and theological claims that conflict with Islamic monotheism. Ibn Hazm is sometimes working from imperfect or variant Arabic translations, and some of his textual arguments rest on misreadings, but the overall exercise is impressively thorough and methodical for its time and context.

The sections on Islamic theological sects reflect Ibn Hazm's Dhahiri standpoint. He is critical of the Mutazilah for their excessive reliance on rational speculation and their willingness to subordinate textual evidence to rational conclusions. He is also critical of the Ash'ari school, despite their Sunni credentials, for what he sees as excessive compromise with kalam methodology. The Hanbali position — which aligns most closely with his own emphasis on textual evidence — receives more respectful treatment, though he disagrees with Hanbali jurisprudence on many specific legal questions.

Ibn Hazm's treatment of Sufi thought and practice is skeptical and often hostile. He applies his standard of explicit textual evidence to Sufi claims and finds many of them lacking. His critiques of specific Sufi practices and doctrinal positions anticipate later critiques by scholars like Ibn Taymiyyah, though the two differ significantly in other respects.

The Dhahiri principle runs through all of Al-Fisal as a unifying methodological commitment: the test for any religious claim is whether it can be grounded in clear, explicit divine communication, untainted by human addition, interpretation, or speculation. By this standard, Ibn Hazm finds both non-Islamic religions and many Islamic positions deficient. His Islam is the Islam of clear text, applied consistently — sometimes to positions that his contemporaries found uncomfortably radical.