"I think, therefore I exist" -- Rene Descartes

Philosophy, An introduction to the Art of Wondering - Sixth Edition -- pages 36/37 | 1994 | James L. Christian

[thinktwice]

Descartes was a geometrician. He found only in mathematics and geometry the certainty that he required. Therefore, he used the methods of geometry to think about the world. Now, in geometry, one begins with a search for axioms, simple undeniable truths – for example, the axiom that a straight line is the shortest distance between two points. On the foundations of such “self-evident” propositions, whole geometrical systems can be built.

Following his geometrical model, Descartes proceeds to doubt everything – de onmibus dubitandum. He will suspend belief in the knowledge he learned from childhood, all those things “which I allowed myself in youth to be persuaded without having inquired into their truth.” Doubt will be his method, a deliberate strategy for proceeding toward certainty. (Descartes is a doubter not by nature, but by necessity. What he really wants is secure understanding so he can stop doubting.)

Descartes finds that he has no trouble doubting the existence of real objects/events – our senses too easily deceive us. And we can doubt the existence of a supernatural realm of reality – figments and fantasies are too often conjured by our native imaginations. But now his geometrical model pays off: in trying to doubt everything, he discovers something that he can’t doubt. What he can’t doubt is that he is doubting. Obviously, I exist if I doubt that I exist. My doubt that I exist proves that I exist, for I have to exist to be able to doubt. Therefore I can’t doubt that I exist. Hence, there is at least one fact in the universe that is beyond doubt. “I am, I exist is necessarily true each time that I pronounce it, or that I mentally conceive it.

Descartes thus becomes the author of the most famous phrase in Western philosophy: Cognito ergo sum, or, in his original French, Je pense, donc je suis. – I think, therefore I exist. With roots in St. Augustine, this is certainly one of the catchiest ideas yet created by the human mind.

[thinktwice]

What I called ambiguities in your post 150, which states ...
Artistotle's definition of man as a rational animal is a definition of man's nature; however, the agent of behavior is a person, not his nature. A person's choice to act irrationally by, say, killing himself, would not make him a non-human person, or, by extension, make his suicide non-human behavior.
... is better classified as the "Soul-Body Dichotomy" by Ayn Rand ... in the following words from her novel Atlas Shrugged.

They have cut man in two, setting one half against the other. they have taught him that his body and his consciouness are two enemies engaged in deadly conflict, two antagonists of opposite natures, contradictory claims, incompatible needs, that to benefit one is to injure the other, that his soul belongs to a supernatural realm, but his body is an evil prison holding it in bondage to this earth -- and that the good is to defeat his body, to undermine it by years of patient struggle, digging his way to that glorious jail-break which leads into the freedom of the grave.

They have taught man that he is a hopeless misfit made of two elements, both symbols of death. A body without a soul is a corpse, a soul without a body is a ghost -- yet such is their image of man's nature: the battleground of a struggle between a corpse and a ghost, a corpse endowed with some evil volition of its own and a ghost endowed with the knowledge that everything known to man is non-existent, that only the unknowable exists.

Do you observe that human faculty that doctrine was designed to ignore? It was man's mind that had to be negated in order to make him fall apart. Once he surrendered reason, he was left at the mercy of two monsters whom he could not fathom or control: of a body moved by unaccountable instincts and of a soul moved by mystic revelations -- he was left as the passively ravaged victim of a battle between a robot and a dictaphone.

[eastsider]

I said nothing about the soul or the body. I merely pointed out that a person (in Aristotelian terms, a primary substance) is the agent of behavior, not his nature (in Aristotelian terms, a secondary substance).

[thinktwice]

Person, nature -- Soul, body -- See the connection?

[eastsider]

Person, nature -- Soul, body -- See the connection?

The Aristotelian primary/secondary substance distinction was not synonymous with the Aristotelian soul/body distinction. For Aristotle, a primary substance could exist by nature, like an individual person, or it could exist by art, like a statue. And the secondary substances -- species and genus (as in man (species) is a rational animal (genus)) -- did not have bodies.

[thinktwice]

From my post 61 ...
"Truth is the product of the recognition (i.e., identification) of the facts of reality. Man identifies and integrates the facts of reality by means of concepts. He retains concepts in his mind by means of definitions. He organizes concepts into propositions -- and the truth or falsehood of his propositions rests, not only on their relation to the facts he asserts, but also on the truth or falsehood of the definitions of the concepts he uses to assert them, which rests on the truth or falsehood of his designations of essential characteristics." -- Ayn Rand, Introduction to Objectivist Epistemology (1979, page 63)

From your post 164 ...
The Aristotelian primary/secondary substance distinction was not synonymous with the Aristotelian soul/body distinction. For Aristotle, a primary substance could exist by nature, like an individual person, or it could exist by art, like a statue. And the secondary substances -- species and genus (as in man (species) is a rational animal (genus)) -- did not have bodies.

Compare Rand's words to your explanation about Aristotle's primary/secondary substance distinctions, and you can see how Rand improved on Aristotle's epistemology. Rand's work reflects 2000+ additional years in knowledge and technology advances, and she presents her epistemology in a clear and concise manner.

Meanwhile, the context of your final words ... (as in man (species) is a rational animal (genus)) -- did not have bodies ... seems to contradict what you're saying.

[zencycler]

The basic premise of Descartes is that an Action (thinking) proves existance (being). Later, Sartre asserted the opposite opinion, that existance (I do) brings forth action (I be). So to paraphrase, here is the evolution of philosophy in a nutshell:

Descartes: I Do Therefore I Be.

Sartre: I Be Therefore I Do.

And let's not forget....


Sinatra: Do Be Do Be Do

[eastsider]

Meanwhile, the context of your final words ... (as in man (species) is a rational animal (genus)) -- did not have bodies ... seems to contradict what you're saying.

Genus and species are rational concepts. They have no bodies. If you're suggesting otherwise, I'm all ears.

Compare Rand's words to your explanation about Aristotle's primary/secondary substance distinctions, and you can see how Rand improved on Aristotle's epistemology.

I seriously doubt that Ayn Rand herself would have considered the proposition that one's nature (in Randian terms, a defined concept), rather than the person, is the agent of human behavior an improvement.

[thinktwice]

I seriously doubt that Ayn Rand herself would have considered the proposition that one's nature (in Randian terms, a defined concept), rather than the person, is the agent of human behavior an improvement.

Question -- An improvement to what?

Comment -- Ayn Rand would probably say that one's nature is a subset of one's person -- leaving the person being the agent of one's behavior. The "God made me do it" defense won't work in the real world.

[eastsider]

An improvement to what?

To Aristotle's distinction between a primary substance (in this case, an individual person as agent) and a secondary substance (the specie and genus as nature of a primary substance).

Ayn Rand would probably say that one's nature is a subset of one's person -- leaving the person being the agent of one's behavior.

I'm stunned. To me, the proposition "man is a rational animal" indicates that an individual person belongs to the set man (specie), which in turn belongs to the set animal (genus), not vice versa.

[thinktwice]

When it comes to classifying living things, the Linnaeus sequence is class, order, genus, and species; so yes, an individual person belongs to the set man (specie), which in turn belongs to the set animal (genus).

Man's nature, however, is not among Linneaus sequence elements because man's nature is an individual characteristic included amongst other individual characteristics such as skin color, sex, intelligence level, etc.

And so it is that one's nature is amongst the characteristic subset of one's person, which still leaves the person being the agent of one's behavior.

[B-Chan]

Well, you've never read Rand's "Introduction to Objectivist Epistemology" because -- in that work -- she improves substantially upon Aristotle's work,

LOL! So Ayn Rand one-ups the Tutor of Alexander, eh?

Thanks for the best laff of the evening! Somewhere, I think, Aristotle must be chuckling, too. "Improves upon Aristotle" indeed!

[thinktwice]

So Ayn Rand one-ups the Tutor of Alexander, eh?

Yep; in epistemology, esthetics, politics and ethics.

Aristotle's work was brilliant; but ... there's always room for improvement and ... IMHO ... she's done it

[eastsider]

Man's nature, however, is not among Linneaus sequence elements because man's nature is an individual characteristic included amongst other individual characteristics such as skin color, sex, intelligence level, etc.

Look at the first two words of the sentence in italics above: "man's nature." If we were discussing an individual characteristic, those first two words would be "Socrates' nature," "Ayn's nature," etc., not "man's nature." "Man's nature" (i.e., human nature) necessarily implies that there is a common nature that is shared universally by all particular men. Universals comprise particulars, not vice versa.

[thinktwice]

Man's nature" (i.e., human nature) necessarily implies that there is a common nature that is shared universally by all particular men.

No it doesn't, the word "nature" is "1. the essential characteristic of a thing; quality or qualities that make something what it is; essence 2. inborn character; innate disposition; inherent tendencies of a person"

The quote is from Webster's New World Dictionary, with bold type used to emphasize connections between the word "nature" and individual characteristics ... "of a person".

[eastsider]

Not "nature," TT. Man's nature.

[thinktwice]

Man's nature" (i.e., human nature) necessarily implies that there is a common nature that is shared universally by all particular men.

Why not provide some expanation as to what you mean by "common nature shared universally"?

[thinktwice]

There is a scene in Ayn Rand's novel Atlas Shrugged describing what I think your view on "Man's nature" is. That scene, describing a train wreck, is posted on Free Republic at http://www.freerepublic.com/forum/a3a84bd4613e0.htm.

For those not visiting that link, one excerpt reads ...

The man in Drawing Room B, Car No. 4, was a newspaper publisher who believed that men are evil by nature and unfit for freedom, that their basic interests, if left unchecked, are to lie, to rob and to murder one another.

For those interested, there are some uniquely interesting Freeper reviews of Atlas Shrugged at click here.

[eastsider]

We seem to be talking past each other. All I’m trying to do is to defend Aristotle’s “Man is a rational animal” from the hideous construction that “irrational behavior is non-human behavior” (see post #149, above).

Aristotle classifies all living things according to a hierarchy of faculties. the faculty of nutrition (which Aristotle relates to reproduction); the faculty of sensation; and the faculty of reason. All living things have the faculty of nutrition/reproduction; some have the faculty of sensation; and only one has the faculty of reason. Plants have the sole faculty of nutrition/reproduction; animals have the additional faculty of sensation; and only man has the additional faculty of reason. So, when Aristotle defines man as a rational animal, he is classifying man as a living thing according to this hierarchy of faculties.

Concerning the faculties, we can distinguish between faculty as capacity and faculty as the exercise of that capacity. All men, by definition, have the capacity to reason, but not all men exercise that capacity. When a man exercises the capacity to reason, he is acting rationally; when he doesn’t, he is acting irrationally. Either way, the behavior is human because the agent is human.

[thinktwice]

Thank you for hanging in there, and I'd like to revise my post 149 statement as follows ...

Humans, by definition, are rational beings; meaning that irrational behavior is non-human anti-life behavior.

Researching Ayn Rand on the subject of irrationality, here's what I found ...

"Man's basic vice, the source of all his evils, is the act of unfocusing his mind, the suspension of his consciousness, which is not blindness, but the refusal to see, not ignorance, but the refusal to know. Irrationality is the rejection of man's means of survival and therefore, a commitment to a course of blind destruction; that which is anti-mind is anti-life." -- from The Objectivist Ethics by Ayn Rand.

[eastsider]

"Man's basic vice, the source of all his evils, is the act of unfocusing his mind, the suspension of his consciousness, which is not blindness, but the refusal to see, not ignorance, but the refusal to know. Irrationality is the rejection of man's means of survival and therefore, a commitment to a course of blind destruction; that which is anti-mind is anti-life."

Ethically speaking, I find a lot of common ground between Ayn Rand and Aristotle. For Aristotle, the greatest virtue is the excellent exercise of the faculty of reason (the highest faculty in the hierarchy of faculties), which is wisdom. The highest rational activity is to be found in the contemplative life, which is what Aristotle says at the very end of the Nichomachean Ethics, in Book X.

Aristotle defines virtue as the mean between the two vices of deficiency and extreme. For example, the virtue of Courage lies between cowardice and foolhardiness. Aristotle doesn't indicate the two vices with regards to the virtue of Wisdom. I suppose the deficiency might be something like sophistry, but I don't know what the excess would be. It's possible that, for Aristotle, Wisdom is like Justice, which Aristotle says is not a mean but an extreme; that is, there is no such thing as an excess of Justice. Since Wisdom is the highest virtue, if the virtue of Wisdom is an extreme like the virtue of Justice, then I could see how refusing to exercise one's capacity to reason (irrationality) would be the greatest vice.