The following is the first attempt which has been made, since the appearance of Munk's excellent sketch, to present in connected form a History of Philosophy in Islam. This work of mine may therefore be regarded as a fresh initiation, -not a completion of such a task. I could not know of all that had been done by others, in the way of preliminary study in this field, and when I did know of the existence of such material, it was not always accessible to me. As for manuscript assistance, it was only in exceptional cases that this was at my disposal.