Not that there is anything wrong with it, but The Secret appears to contain a lot of the same ideas as The Master Key. Both owe a little something to Ralph Waldo Trine’s In Tune With The Infinite, which in turn owes something to late nineteenth-century western mystery tradition and theosophical authors of the time.
It would be interesting to trace the history of these ideas and come up with some kind of “family tree”.
If you know of anyone that is doing this or has done it, please leave a comment.