One explanation concerning why perennialism might be included among a list of those things that cause one to doubt Islam is the acknowledgement that a common perspective among perennialists is to depreciate exclusive religious identity in favor of identity as a metaphysician following the religion of the heart. The notion that Islam was arbitrary and expedient in principle (even if providential) and that neither Guenon nor Schuon can be considered converts is an important point of explanation among some of their followers. In perennialism (considered as a movement with ideological tendencies) this indicates a shift of primacy from revelation toward intellection wherein gnosis supplants the religion of the Prophet Muhammad - May peace and blessings be upon him. Intra-traditionally, a similar confluence of ideas may be found in the interplay of nubuwwah and wilayah. The difference is that this interplay occurs within an Islamic context wherein the intellect is still viewed as a ray of the nur muhammadiyah rather than a star shining solitarily above a plethora of religious firmaments. I imagine that the initial encounter of such ideas can be somewhat confusing or disconcerting for those who principally or exclusively identify themselves as Muslims, particularly if they have a propensity toward esoterism as taught by these figures.
Especially following the release of the Study Quran, many popular Islamic scholars (in the sense of addressing the populace rather than being in themselves well-known) are portraying the perennial philosophy in its ideological form (i.e. Perennialism) as a threat to the articles of Islamic faith determined by the majority of the community. Anyone who adopts a pluralistic perspective is considered by these scholars to have forfeited the correct view which may be interpreted as a crisis of faith even though it does not involve the introduction of doubt concerning God or Islam. I imagine that many Muslims, presented with a teaching that appeals to their intelligence but which contrasts to the teaching that appeals to their fear of God and desire for salvation will feel themselves deeply conflicted over the matter.
I think that the issue is a little more complicated than Islam reigning among the religions or otherwise abrogating them, and so forth. Islam in fact identifies itself as the religio perennis (din al-fitrah, din al-hanif, and even din unqualified), the haqiqa muhammadiyah as the source of all legislative prophets, and the shahadah as the philosophia perennis or essence of all revealed messages. I wonder how many intellectually inclined Muslims upon being exposed to perennialism think to themselves, why the need for a secular perennial philosophy?
Greetings of Peace. This blog contains selections from my correspondence and other sources on a variety of subjects related to religion, philosophy, and spirituality. I hope that they may be of benefit to the interested reader. Concerning the title of the blog, read this entry.