I wish to express my warmest thanks to the Trustees of the Gibb Memorial Fund for making the publication of this work possible, and especially to Professor Sir Hamilton Gibb, who asked me to undertake the work and who has not only read the proofs but has continually given me his interest and encouragement. I am also deeply indebted to Dr. R. Walzer, who has read the proofs, carefully checked the references in my notes, and composed the indexes and the Greek-Arabic and Arabic-Greek vocabularies. I have also to thank Dr. S. M. Stern for his help in completing the subject-index. Finally, I wish to pay a tribute to one who is no longer amongst us, Father Maurice Bouyges, without whose admirable text the work could never have been undertaken.

The marginal numbers in Vol. I refer to the text of Father Bouyges’s edition of the Tahafut al Tahafut in his Bibliotheca Arabica Scholasticorum, vol. iii, Beyrouth, 1930.

The asterisks indicate different readings from those to be found in Bouyges’s text: cf. the Appendix, Vol. I, pp, 364 ff.