TL;DR
5/10. A New Thought classic from 1963, still selling, and one of the sources everything from The Secret onward is drawing on. There is a defensible idea at the center about suggestion and expectation. Around it is a great deal that is not supportable and is presented with total confidence.
Murphy’s frame is that the mind has two parts. A conscious one that reasons, selects, and rejects, and a subconscious one that accepts instruction without judgment and works to produce whatever is impressed upon it.
Prayer, affirmation, and visualisation are all in his account methods of impressing the subconscious, and the practical instruction is to do it at the boundary of sleep, when the conscious mind is least able to interfere.
He was a minister in the Divine Science tradition, part of the New Thought movement that also produced Ernest Holmes and connects back to Phineas Quimby in the nineteenth century. The book is theology written in the vocabulary of psychology, and knowing that changes how you read it.
What holds up?
Expectation shapes behavior, and behavior shapes outcomes.
A person who believes an interview will go badly arrives differently. They prepare less, or they prepare anxiously. They read neutral expressions as disapproval. They give shorter answers. The belief participates in producing the result, and afterward it looks like confirmation.
That is real, it is well studied under other names including expectancy effects and self-fulfilling prophecy, and Murphy gets to it decades before it was popular. He does not have the mechanism right, and the observation is sound.
The material on sleep is also better than its surroundings. Handing a problem to your mind before sleeping and finding it clearer in the morning is something most writers have experienced, and there is respectable research on sleep and problem consolidation. His description of the practice is practical and matches what a great many working people do without a theory attached.
What does not hold up?
The healing claims, and they take up a substantial portion of the book.
The assertion that the subconscious can cure organic disease is presented flatly and repeatedly. The case stories arrive with no verification, no names that can be checked, no follow-up, and enormous confidence. A man is told he has weeks to live, changes his thinking, and is well.
The mechanism proposed is not a mechanism. Saying the subconscious controls all bodily functions and will restore health if properly instructed does not describe a process, it restates the claim in different words.
The same objection I raised about Louise Hay applies here and it originates here. If mind produces outcome, then a bad outcome is a failure of mind, and that logic reaches people at their most vulnerable and tells them the fault is theirs.
Why does The Power of Your Subconscious Mind still matter?
Because almost everything in the modern manifestation genre is downstream of it, and reading the source explains the descendants.
The Secret, the law of attraction industry, a large part of the visualisation material in sports and business coaching, and much of what Hay House publishes all trace back through this book to New Thought. The vocabulary changed and the structure did not.
Reading Murphy directly is more useful than reading the modern versions, because he is clearer about what he is claiming. Later writers wrapped the same argument in quantum language and neuroscience vocabulary to make it sound contemporary, and Murphy simply asserts it, which at least lets you see the assertion.
How should you read The Power of Your Subconscious Mind?
As a historical document with a usable core, and with the healing chapters treated as what they are.
Take the expectation material, which is sound. Take the sleep practice, which is harmless and frequently works for reasons Murphy did not have. Notice the structure of the argument, because you will meet it again in a hundred other books.
And treat the healing material as a religious claim in psychological clothing, which is what it is. Murphy was a minister making a claim about the divine mind, and translating it into the language of psychology does not turn it into psychology.
Verdict
Historically important and largely superseded. Read it to understand where this whole genre comes from, since almost everything since is downstream of it.
Take the expectation material, which is sound, and treat the healing material as what it is, which is a religious claim in psychological clothing.
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