Crowley's Book of Wisdom and Folly must certainly be taken with pinches of salt here and there, and the reader must be prepared to skip parts altogether as nonsense. The reader must also be male - women are likely to throw the book away after the first page.
That said, The Book must be read for some of the magnificent insights, found elsewhere in Crowley's writings, but not in 'standard' books of 'philosophy'... this is not a philosophical work; neither is it Satanic, or any other label people have given it.
It is impossible to write a brief review of The Book, partly because of its 'heterogeneous' composition, lacking any central theme- seen from the point of view of a non-gnostic. For the general reader interested in finding - there is no other word for it but 'magnificent'- magnificent insights into ... into? This reviewer cannot even say insights into what.
The tone of authority here will be appreciated by some and criticized by others.
This reviewer is being as rambling as Crowley is in The Book- but if one cares to look through the rambling, the insights- indeed, truths- have the power to transform people's attitudes to philosophy, even people's philosophies.
Read The Book if you will to do so. Those readers who are struck by the first declaration of 'The Law' - and possibly only those readers- must read The Book: Do what thou wilt shall be the whole of the Law.