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Descartes's Secret Notebook: A True Tale of Mathematics, Mysticism, and the Quest to Understand the Universe

Descartes's Secret Notebook: A True Tale of Mathematics, Mysticism, and the Quest to Understand the Universe [Kindle Edition]

Amir D. Aczel
4.0 out of 5 stars  See all reviews (2 customer reviews)

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Product Description

Product Description

René Descartes (1596—1650) is one of the towering and central figures in Western philosophy and mathematics. His apothegm “Cogito, ergo sum” marked the birth of the mind-body problem, while his creation of so-called Cartesian coordinates has made our intellectual conquest of physical space possible.

But Descartes had a mysterious and mystical side, as well. Almost certainly a member of the occult brotherhood of the Rosicrucians, he kept a secret notebook, now lost, most of which was written in code. After Descartes’s death, Gottfried Leibniz, inventor of calculus and one of the greatest mathematicians of all time, moved to Paris in search of this notebook–and eventually found it in the possession of Claude Clerselier, a friend of Descartes’s. Liebniz called on Clerselier and was allowed to copy only a couple of pages–which, though written in code, he amazingly deciphered there on the spot. Liebniz’s hastily scribbled notes are all we have today of Descartes’s notebook.

Why did Descartes keep a secret notebook, and what were its contents? The answers to these questions will lead the reader on an exciting, swashbuckling journey, and offer a fascinating look at one of the great figures of Western culture.

From the Hardcover edition.

Product details

  • Format: Kindle Edition
  • File Size: 1203 KB
  • Print Length: 288 pages
  • Publisher: Broadway Books (19 Feb 2009)
  • Sold by: Amazon Media EU S.à r.l.
  • Language: English
  • Text-to-Speech: Enabled
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  • Average Customer Review: 4.0 out of 5 stars  See all reviews (2 customer reviews)
  • Amazon Bestsellers Rank: #702,194 Paid in Kindle Store (See Top 100 Paid in Kindle Store)
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Most Helpful Customer Reviews
1 of 1 people found the following review helpful
4.0 out of 5 stars Entertaining biography 30 Dec 2013
Format:Kindle Edition|Verified Purchase
This is a short, lively and entertaining book which was a pleasure to read.
One other review at least stated that it was less about the notebook and more a biography, and this is a sound analysis. However, the notebook is the central idea which the biography leads up too, so, although the title is a misnomer, it at least describes the final thoughts of the book.
I would recommend this to anyone interested in Descartes' life and time, or the development of his thought. It is a good primer, and quite entertaining. However, it is basically a biography which is not suggested by its title, so give it a miss, or just slim the final chapters, if that is not what you are after.
The writer is a good communicator of complex ideas and writes in an entertaining style, my one complaint betting several typo's.
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1 of 1 people found the following review helpful
4.0 out of 5 stars Careful... don't tell anyone but... 9 Mar 2013
By Biro
Very good account of Descartes' life and an enjoyable read. Not much about the secret notebook though. Interesting links to Liebniz. Will not say what was in the notebook as it will spoil the read! Also gives an insight as to how religion (or should that be the church - you decide), obstructed learning.
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Most Helpful Customer Reviews on (beta) 3.4 out of 5 stars  37 reviews
27 of 27 people found the following review helpful
3.0 out of 5 stars Discombobulating 16 Feb 2006
By P. Wung - Published on
I had read Amir Aczel's book on Fermat's Last Theorem, and I felt the same way, more confused than enlightened. The problem is that Mr. Aczel has a less than interesting style: the reading goes by very quickly and it just does not feel like one is gaining a lot of facts when one is gaining some facts. I thought Simon Singh did a better job with Fermat and I can't help but think that someone else can do a better job with this material.

It seems like Mr. Aczel has better things to do and more things to say at the end of the book, so he rushes to get to the good stuff only to reveal that there is very little good stuff.

Rene Descarte has always been a very interesting person to me. I had read a rather extensive biography of the man many years ago as an undergrad, so what Mr. Aczel had to bring to the story is interesting but not surprising. He does a pedantic job of relating the basics with some interesting tidbits thrown in, yet his style makes the interesting seem superficial.

The entire time, Mr. Aczel is moving towards the big mysterious reveal, the reason for yet another Descarte biography. He keeps hinting at a great earthshattering surprise, yet when it does come, the surprise is hardly surprising. The ingenious work that Descarte did in defiance of the church authorities of his day is indeed impressive but Mr. Aczel does not do the revelation justice. He never fully engages the reader in the development of the discovery and he fails to explain the difficulty of the mathematic is ignored altogether.

It is a good short treatment of Descarte's life, but there is no heft, very little mathematical detail, and nonexistent mystery in what is promised as a mysterious and revelatory book.
27 of 29 people found the following review helpful
1.0 out of 5 stars I guess this is a memoir? 10 Feb 2006
By John Montucla - Published on
James Frey has taught us that it's OK to call a work of non-fiction that isn't entirely true a memoir. So maybe this is book is also a memoir?

Aczel has received a number of positive reviews on this book, for example from a Boston newspaper and from two of Amazon's "Top Reviewers." But none of these people are actually competent to judge the contents of the book. All they can really do is summarize what's there and say that they enjoyed reading it.

As is well documented by other reviewers, this book is mostly just a biography and actually has very little about the secret notebook. Aczel does a reasonably good job of summarizing these secondary sources, but almost nothing else he says is true. For example, he says that Descartes invented the ruler and compass construction of the square root and says that the Greeks didn't know how to do this. If any real historian of science had looked over his manuscript, this boner never would have appeared in print. The publisher should be ashamed for propagating such misinformation. If they'd spent a little time and a couple of bucks having a real historian of mathematics review the manuscript, this sort of pathetic error could have been corrected. But the publisher and the author apparently have such contempt for the reading public that they don't care if they publish falsehoods. Or maybe they just didn't want to delay a pre-Christmas release date?

This isn't an isolated example. The book is loaded with nonsense, from matheamtical facts to dates to what the fifth element represented in Plato's cosmology. And the really pathetic thing is that almost none of these sophomoric errors has anything to do with the biography of Descartes or with the secret notebook. Aczel seems to have included them as window dressing or page padding or perhaps just a desire to appear learned. It's an old problem: the conceit that any semi-retired mathematician can "deduce" the history of mathematics the way he deduces a theorem, and he doesn't actually have to do any research.

Shame on Aczel and on Broadway publishers. Let the buyer beware!
26 of 29 people found the following review helpful
1.0 out of 5 stars How Can I Trust Anything in this Book? 11 Dec 2005
By Geometric Mean - Published on
I generally enjoyed the biography of the young Descartes in the first few dozen pages of this book. But soon I started reading things about the history of mathematics which I know to be incorrect. So I have to conclude that the book is at least somewhat untrustworthy.

When discussing the duplication of the cube, Aczel says that Eratosthenes was a contemporary of Eudoxus in Plato's Academy, whereas he actually lived more than a century later. Elsewhere on this webpage, Dr. Amir Bernstein dismisses this as "a mere hundred years" and says that "dates of Greek mathematicians/philosophers are known only approximately." Actually, we can date Eudoxus and Eratosthenes quite accurately because Aristotle wrote about Eudoxus' astronomical theories in his _Metaphysics_ and Archimedes dedicated his book _The Method_ to Eratosthenes. Not only did they live more than 130 years apart, but they belonged to completely different mathematical cultures. In between their two lives, there was a philosophical revolution (Aristotle proposed the axiomatic method), a mathematical revolution (Euclid's Elements standardized the practice of geometry) and a social revolution (Alexander's multicultural "cosmopolis" became a reality in Alexandria).

Even such a simple fact such as the year in which Euler first went to St. Petersburg is wrong: it's given as 1730 instead of 1727. Aczel also claims that Euler visited Hanover on this journey. Thiele (1982) gives a very complete chronicle of the journey, based on Euler's own notebook, in his German-language biography, but he makes no mention of Hanover. Tellingly, Aczel gives no citation for his claim, which he uses to bolster his questionable theory that Euler somehow learned his theorem that F+V=E+2 from Descartes' lost notebook.

The biggest error is this claim on page 164: after telling us that Descartes gave a ruler-and-compass construction for square roots, he says "this was one of his greatest achievements in mathematics ... which would have stunned the ancient Greeks since they could construct only much simpler things." Unfortunately, it was not Descartes' discovery, because the construction was, in fact, known to the Greeks. What Descartes presents is just a special case of Proposition 14 from Book II of Euclid's Elements. You need only look at the diagram in Descartes' Geometry (p.4 of the Dover edition) and the one in Euclid's Elements (vol. 1, p. 409, also in Dover) to see this. Yes, one is the mirror image of the other and the letters are different. But the construction is the same. And here's why it works. In II.14, Euclid tells you how to construct a square with an area equal to a given rectangle. If the rectangle has sides of length a and b then its area is ab. Since the area of the square is also ab, the length of each side of the square is the square root of (ab). The Greeks called this the "geometric mean" of a and b, where "mean" is a word we still use today for average. Now what Descartes does is the case b=1, so what he gets is the square root of a. It may seem paradoxical to some, but by constructing a square, Euclid gets a square root along its side.

I think Aczel also gives Cardano too little credit and Tartaglia too much in his story about the solution of the cubic equation, but I'll just refer readers to Boyer & Merzbach (1991, p. 282-286) and Katz (1998, p. 358-364) to make up their own minds.
38 of 44 people found the following review helpful
5.0 out of 5 stars Fascinating Look at the Life, Thought and Mystery That Was Rene Descartes 22 Nov 2005
By Parker Benchley - Published on
To look at a portrait of Descartes, one would consider him somewhat of a fop. And if one were to strictly consider Descartes' contributions to mathematics and philosophy, then he might be seen as a nerdish fop. But this portrait couldn't be farther from the reality that was Descartes' life. He was a world traveler and adventurer in addition to being one of the most brilliant minds the world has produced - before or since.

But you wouldn't know it from reading current biographies of Descartes. They are in the main turgidly written tomes; the only excitement they instill in the reader is wondering when they will end. I began to despair of there ever coming into print a biography of Descartes that captures both the thought and details of his fascinating life. Until now.

Amir Aczel combines the life and thought of Descartes in a slim breezy volume with an enthusiasm for his subject rarely seen in this sort of biography. His talent for explaining mathematical ideas and formulas that might seem daunting to the lay reader only adds to our enjoyment and deepens our appreciation for this most prolific philosopher-scientist.

To say Descartes led an interesting life is an understatement, and perhaps the most interesting thing about was the aura of intrigue and mystery in which it was enveloped. Aczel uses this as his starting point, investigating the mystery of Descartes' secret notebook which survived his death and part of which was copied by Leibniz, who easily broke the code in which it was written.

What was in this notebook that was so dangerous that Descartes felt compelled to write it in code? Aczel rightly decides to view the work in context of Descartes' life and thought, examining the charges heard in Descartes' day that he was a Rosicrucian, that he was writing heresy, and embracing the banned theories of Copernicus. Descartes, for his part, feared the Inquisition, especially after learning the fate of Galileo. He sought refuge in Holland, only to become once again embroiled in controversy. He reluctantly accepted an invitation from Queen Christina of Sweden as her personal tutor, thinking perhaps he could leave his detractors behind. But even his death in Sweden a short time later would become controversial. Did he die of natural causes, or did his enemies in the Queen's court, fearing his influence on the Queen, poison him?

And why was Leibniz so interested in copying the notebook? And why were his notes only fully understood in the late Twentieth century? Aczel tackles these issues and offers reasoned explanations based on the facts at hand. All this makes the reader want to know more about the life and thought of Descartes and his times, and that makes Aczel's book a success.
21 of 23 people found the following review helpful
1.0 out of 5 stars Much ado, and by whom? 15 Feb 2006
By Florrie Cajori - Published on
Previous person wonders why so many reviewers hype this book. Isn't it obvious? At least half the reviews here were written by the author himself! Check 'em out: no Real Name (tm) attribution, no other reviews written by the same person, and Google searches turn up no real person by that name in that city. And they all write in that same quirky, fawning style. Check out his other books on Amazon: it happens there, too. I guess he does it to counter negative reviews and to pump up his ratings. The funniest one here is "Michael Bernstein," who claims to have a Ph.D. in the history of science. Sorry, history of science is a small world and there are no Michael Bersteins in it.
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