The Secret Doctrine by H.P. Blavatsky: The Synthesis of Science, Religion and Philosophy-Volumes I and II: Cosmogenesis and Anthropogenesis. (Facsimile of the Original Edition of 1888). Hardback, 1500 pages. Brand New 

Note: This is a metaphysically complex and advanced text which many will struggle to understand if they are not already familiar with simpler works such as "The Ocean of Theosophy" by William Quan Judge and "The Key to Theosophy" by H.P. Blavatsky

Both of these works may also be found through the following links:

https://www.ebay.co.uk/itm/405830920062;  https://www.ebay.co.uk/itm/405830825493