Cincinnati, 3/17/2010
It is my suspicion that the cause of our current malaise is anything but neurological or physiological. That's just too easy, too reductionistic and one-sided ("simple minded"). Geneticists will never isolate the chromosome carrying Sacks Syndrome.

I suspect a hidden philosophical source, a "causative-agent" to be found not just in our physiology but in our history of ideas, for this plague. I want to suggest, in fact, that we rename this debilitating disorder after its true discoverer (or should I say founder?): let us call it "Descartes' Disease." Oliver Sacks may have been the first to describe the disorder's symptoms, but it was René Descartes who first experienced its pathology in its full force when, as a methodological expedient, he found it useful to doubt the reality of the physical in a manner that foreshadows our present pathology. It is the "memes" of Cartesianism which have served as the releaser for this disease. Let us give credit then to the true "evil genius" for his creation.

It might be helpful to remind ourselves of Descartes' chief contribution to the thought of the second half of the second millenium. Allow me to quote Charles Sanders Peirce's concise (not entirely sympathetic) summary of the Cartesian influence.

Descartes is the father of modern philosophy, and the spirit of Cartesianism—that which principally distinguished it from the scholasticism which it displaced—may be compendiously stated as follows:

1. It teaches that philosophy must begin with universal doubt; whereas scholasticism had never questioned fundamentals.
2. It teaches that the ultimate test of certainty is to be found in the individual consciousness; whereas scholasticism had rested on the testimony of sages and of the Catholic Church.
3. The multiform argumentation of the middle ages is replaced by a single thread of inference depending often upon inconspicuous premisses.
4. Scholasticism had its mysteries of faith, but undertook to explain all created things. But there are many facts which Cartesianism not only does not explain but renders absolutely inexplicable, unless to say "God makes them so" is to be regarded as an explanation.

In some or all of these respects, modern philosophers have been, in effect, Cartesians.

He has left us with a theory of mind and thought so influential that its main tenets are still widely held and have barely begun to be reevaluated. It has been handed down from generation to generation as if it were a collection of self-evident truths. Much of it is still taught with reverence.

In brief, the Cartesian picture of mind that we have inherited is this:

• What makes human beings human, the only thing that makes them human and that defines their distinctive nature, is their capacity for rational thought.
• Thought is essentially disembodied, and all thought is conscious.
• Thought consists of formal operations on ideas without regard to the relation between those ideas and external reality.
• Ideas thus function like formal symbols in mathematics.
• Some of our ideas are innate and therefore exist in the mind at birth, prior to any experience.
• Other ideas are internal representations of an external reality.
• We can, just by thinking about our own ideas and the operations of our own minds, with care and rigor, come to understand the mind accurately and with absolute certainty.
• Nothing about the body, neither imagination nor emotion nor perception nor any detail of the biological nature of the body, need be known in order to understand the nature of the mind.