The Magical Knowledge trilogy is a large collection of work by Josephine McCarthy written between 2009 and 2011, originally presented in three paperback volumes as Magical Knowledge I Foundations, Magical Knowledge II The Initiate, and Magical Knowledge III Contacts of the Adepts. It is now presented as a complete hardback collection for the first time. The three individual volumes are still available in their second edition paperback form published by TaDehent Books.

The Magical Knowledge Trilogy is a series that takes the reader through the twists and turns of serious magical study and practice. Written by Josephine McCarthy, one of the world's leading magical adepts, The Magical Knowledge Trilogy covers the necessary skills, contacts, and practices for lone magical practitioners studying and working within Western magic.

It is a sampling of the teaching and magical work undertaken by the author over a twenty-year period, reaching from the early stages of magical practice right up to the adept level of work, and is designed for the lone practitioner. The writing of this collection signalled a turning point in McCarthy's work, as it began to develop more towards the in-depth training of magicians, which eventually manifested in the form of Quareia: an open source magical training course of unparalleled depth and scope.

The trilogy covers magical advice, techniques for ritual, visionary work, utterance, divination, and sigil-making, and includes essays on the history of magic and a look at the mythic storytelling tradition.

Josephine McCarthy is a Western magical adept living in the Southwest of England. An esoteric practitioner, teacher, and author, she has written over thirty books on magical theory and practice, including The Exorcist's Handbook, Magic of the North Gate, The Book of Gates - a Magical Translation, and Tarot Skills for the 21st Century. Josephine has taught extensively in the USA and UK since the early 1990s, and has lectured at various occult, esoteric, and hermetic conferences in the UK and USA. She is the designer and book author for the LXXXI Quareia Magician's Deck (2014 Quareia Publishing UK), produced with artists Stuart Littlejohn and Cassandra Beanland.

McCarthy is also the author of Quareia, an extensive, in-depth, open source online training course in the theory, practice, and history of Western magic, which seeks to move Western magical practice into a deeper, more cooperative relationship with nature and the environment.