[8] Byrne re-introduces a notion originally popularized by persons such as Madame Blavatsky and Norman Vincent Peale that thinking about certain things will make them appear in one's life.

[11] Due partly to an appearance on The Oprah Winfrey Show, the book and film had grossed $300 million in sales by 2009.

If you ignore The Secret's far-too-simplistic maxims (no, you will not be doomed to a miserable life for thinking negative thoughts) and the hocus-pocus (the cosmos isn't going to deliver a new car; it's busy), there's actually some helpful advice in the book.

[16][17] Mark Manson, author of The Subtle Art of Not Giving a F*ck, is one of the harshest critics,[citation needed] writing that the book is "full of misplaced clichés, silly quotes, and superstitious drivel", and calls it a "playbook for entitlement and self-absorption", which "anybody who reads it and implements its advice ... will likely make themselves worse off in the long run".

[19] Byrne's scientific claims, in particular concerning quantum physics, have been rejected by a range of authors including Christopher Chabris and Daniel Simons at The New York Times[20] and Harvard physicist Lisa Randall.

[21] Mary Carmichael and Ben Radford, writing for the Center for Inquiry, have also pointed out that The Secret has no scientific foundation, stating that Byrne's book represents "a time-worn trick of mixing banal truisms with magical thinking and presenting it as some sort of hidden knowledge: basically, it's the new New Thought.