Here's a stunning collection of rare occult books from the Monash University Library in Australia. From the 1998 exhibition catalog:
"So great is the variety of 'occultisms,' that it is often difficult to find any connecting link between these traditions. The word is derived from the Latin, occullere, to cover over, to hide, or conceal, and all occult belief systems lay claim to some esoteric or hidden knowledge, but so too do many religions and mystical and philosophical systems, which are not defined as 'occult'. It is also clear – at least as far as those 'occult systems' with their own complex cosmologies are concerned – that what might be perceived by an outsider as "occultism", is to the practitioner quite possibly religion. This difference of perception serves to underline the only definite link that can clearly be demonstrated between these disparate 'occultisms': all were (or are) belief systems which existed (or exist) either on the margins of, or altogether outside, the mainstream religious or philosophical orthodoxies of the cultures in which they evolved." Link
