Martin Lings - Metaphysics & the Perennial Philosophy

Wikipedia:

"Martin Lings (also known as Abu Bakr Siraj Ad-Din) (January 24, 1909 – May 12, 2005) was an English writer and scholar, a student and follower of Frithjof Schuon, and Shakespearean scholar. He is best known as the author of a very popular and positively reviewed biography, Muhammad: His Life Based on the Earliest Sources, first published in 1983 and still in print.
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For Lings himself, however, the most important event whilst at Oxford was his discovery of the writings of the René Guénon, a French metaphysician and Muslim convert, and those of Frithjof Schuon, a German spiritual authority, metaphysician and Perennialist. In 1938, Lings went to Basle to make Schuon's acquaintance and he remained Frithjof Schuon's disciple and expositor for the rest of his life." 

Martin Lings - Metaphysics & the Perennial Philosophy