© Tom Graves 1980 
The work of the late Tom Lethbridge covers a vast range of themes and areas of research, far beyond any mere category like ‘parapsychology’, and each of these themes appears in almost every book. And his wandering from theme to theme, and anecdote to anecdote, is not as casual as it seems: his anecdotes and digressions were selected with deceptive care, and his loose rambling style conceals a concise and meticulous planning of the presentation of his ideas. It is difficult to edit this without destroying the sense, the style or the continuity, of all of them – and it is these that are the essence of Tom Lethbridge’s writing.
What we have done is to select three of the major themes of his work, and develop these with his own digressions and interconnections to his other themes. These major themes are stated by Lethbridge himself at the end of Ghost and Ghoul: that ghosts are pictures produced by human minds, rather than the spirits of the departed; that there is something entirely wrong with our conception of time; and that magic, in the traditional sense, is the application of resonance, the interconnection of all things.
These themes lie behind the work on ghosts and energy fields in Ghost and Ghoul; dowsing in Ghost and Divining Rod and A Step in the Dark; perception in ESP; dreams and precognition in The Power of the Pendulum; and the questioning of the theory of chance evolution in The Monkey’s Tail. These form the bulk of the first eight chapters of this abridgement and are presented in what seems to us to be the most logical sequence: from ghosts and field theory, through the uses of dowsing and psychometry, to a theory of a ‘master plan’ beyond evolution and physical death.
The work on archaeology and the old gods, as developed in Gogmagog and Witches, does not connect directly with this sequence, although it is essential to the unity of his work; but Lethbridge refers to it often in his other books, and we have included and expanded these references wherever practicable.
We have been forced to leave out much of the detail of his research on the old beliefs and on the stone circles and standing stones, but this is inevitable in an abridgement of this nature. But the development of these ideas, connected back to the sequence we have developed here, culminated in the work presented in The Legend of the Sons of God, which we have used as a theme for the last two chapters of this edition. It covers the same area that was made notorious and disreputable by von Däniken and his followers; but Lethbridge, as he himself explains, covered it independently of von Däniken and, unlike the latter, presents several credible alternative explanations of this difficult material.
 Source: The Essential T.C. Lethbridge edited by Tom Graves and Janet Hoult with a foreword by Colin Wilson ; Routledge & Kegan Paul Ltd, London, 1980, ISBN 0 586 05077 9.