This primer on the astral plane--the fine-material world in which we are all immersed without generally being aware of it--gives a quick overview of that world, with an emphasis on the beings who inhabit it (besides ourselves). This book, originally published in 1896 as Theosophical Manual No. 5, was written to summarize the findings of the Theosophical Society, whose literature was extensive and, for many people, abstruse.
The astral world is vast and complex, with many different kinds of denizens at various levels of spiritual awareness and moral goodness. One of the most intriguing parts for me was the author's description of "elementals": astral beings that are created by our thoughts. Every thought that we have, especially those that express desires, wishes, or intentions, creates an astral being that functions as a kind of bot that seeks to realize that desire, whether positive or negative. Weak passing fancies generate elementals that live only briefly; strong wishes that are thought of again and again create more robust elementals that endure for days, weeks, or years, depending on how often we revert to that thought. Since most of our thoughts are selfish, we are all attended by a kind of retinue of astral elementals that seek to prolong their own existence by encouraging us to keep thinking or wishing. On the other hand, when we have positive wishes or prayers for others, the elementals go to those others and work to bring about the positive thing that has been wished for.
There's much else in this book, as well. If you're of a materialistic cast of mind and don't believe in the existence of anything except what you can touch, then it will seem quite strange and incredible. Indeed, I found it to be that way, and I firmly believe in the astral realm and other orders of reality beyond the tangible. This book acquainted me with the clairvoyant discoveries of the Theosophical Society in the 19th century. Those people, like the rest of us, are limited by their own prejudices and levels of understanding; but they have performed a great service to us all, I think, for they have thrown some light on the great unknown continent that is each one of us and the much vaster world that we really live in.