23rd may 1930 was when Einstein wrote the preface to Sinclair's book. Copy right prevents me from repeating it all here, but the essence are the sentences where he says it is not likely a person like Sinclair has set out to deceive all his readers, and this book should be read by all interested in psychology. Good enough for me!
And tell you what - it is on my kindle now, already. 10 minutes since I got it after clicking on your link.

The preface does not seem to be on the kindle, which is a pity, but let me have a good look first. I read the German version of Einsteins preface too and understood most of it and then read the English translation.

Einstein recommends the book!

Now it sits in my kindle right between the two about Einstein.

GG.


Itatw70s Wrote:
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> [archive.org]
> ntalradio017719mbp_djvu.txt
>
> This is the exclusive book, reviewed by Mr.
> Sinclair's friend, Albert Einstein in the Preface
> to the book. Read the English version following
> the German Preface.
>
> With this, I have done my Homework. See what is
> possible in Scientific Research.