On the brighter side:

“Rational or reasonable is everywhere synonymous with consistent or logical, as also conversely. Indeed logic is simply the natural method of the faculty of reason itself, expressed as a system of rules. Therefore those expressions (rational and logical) are related to each other as practice to theory. In precisely this sense we understand by a rational way of acting one that is entirely consistent, starts from general concepts, and is guided by abstract thoughts as resolutions; but not one that is determined by the fleeting impression of the moment.” —Arthur Schopenhauer, On the Fourfold Root of the Principle of Sufficient Reason (1813)

“Rational animals are conscious, rule-following, intentional (that is, possessing capacities for object-directed cognition and purposive action), volitional (possessing a capacity for willing), self-evaluating, self-justifying, self-legislating, reasons-giving, reasons-sensitive, and reflectively self-conscious—or, for short, normative-reflective—animals, whose inner and outer lives alike are sharply constrained by their possession of concepts expressing strict modality. Modality in the philosophical sense comprises the concepts of necessity, possibility, and contingency. Strict modality, in turn, includes the concepts of logical necessity (truth in all logically possible worlds), epistemic necessity (certainty or indubitability), and deontic necessity (unconditional obligation or ‘the ought’). So, to put my first central claim yet another way, logic is cognitively constructed by all and only those normative-reflective animals who are also in possession of concepts expressing strict modality.” —Robert Hanna, Rationality and Logic (2006)

“Rationality provides us with the (potential) power to investigate and discover anything and everything; it enables us to control and direct our behavior through reasons and the utilization of principles.” —Robert Nozick, The Nature of Rationality (1993).

Other contemporary works on rationality:

The Architecture of Reason: The Structure and Substance of Rationality (2001)

Robert Audi

Rationality in Action (2001)

John Searle

The quote from Robert Hanna:

...Modality in the philosophical sense comprises the concepts of necessity, possibility, and contingency. Strict modality, in turn, includes the concepts of logical necessity (truth in all logically possible worlds), epistemic necessity (certainty or indubitability), and deontic necessity (unconditional obligation or ‘the ought’).

This terminology (logical “necessity, possibility, and contingency”) belongs to so-called modal logic, and that whole way of thinking is fundamentally wrong.  Modal logic is an outgrowth of the analytic-synthetic dichotomy, which Objectivism completely rejects.  In this view, “necessary truths” are limited to statements true “by definition,” and everything else is “accidental” because we can "conceive" of it as being different.  The notions of logical necessity, possibility and contingency derive from the view that certain things “happen” to be true but “could have been otherwise.”   This is only true with respect to the man-made, not metaphysical reality. 

Per the Law of Identity, the way things are is inherent in the nature of the things that exist. To speak of “other possible worlds” is to adopt a Platonic/religious world-view, and that is obviously a complete departure from Objectivism.  Classifying logical truths based on their alleged “contingency” or “necessity” is not consistent with a proper view of rationality.

I would characterize “animals, whose inner and outer lives alike are sharply constrained by their possession of concepts expressing strict modality” as skeptics or worse.

Ed,

Thanks, but considering the beautifully eloquent job you did on this article, and all the work you evidently invested in the project, my post was little more than a footnote.

[In other words:  “Aw, shucks.  Weren’t nothin’.”  It’s hard to be humble when you’re so f-ing brilliant, ain’t it?  But we try.]  J

I entertained the idea of posting this bugger as an RoR article – but decided against making it THAT readable!

For those who find themselves to be in possession of the wherewithal to get through it, it effectively reverses 21 centuries of wrong-headed thought regarding the art and science of logic (which some might find as something of tremendous value). Check it out …

The Fallacy of the Existential Fallacy (an “anti-fallacy”)

PROBLEM (a wonderfully-illustrative instance of the thinking-error entitled: Existential Fallacy)

Barry Miller, a philosophy editor for Stanford wrote a piece that’s retrievable from:

http://plato.stanford.edu/entries/existence/ [retrieved 5 March 2008]

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… Unlike the Frege-Russell thesis, Aquinas did not regard these three uses of ‘is’ as being totally unrelated.

 

A crucial difference between Aquinas and Avicenna, however, lies in the distinction he draws between two existential uses of ‘is’. In one of them, ‘is’ is taken to express the being of whatever falls under the Aristotelian categories, whether it be of substance or of any of the accidents. As used in this way, ‘is’ refers to that by which something is actual. In the second existential sense, however, it expresses the truth of a proposition. Following Geach, these two existential uses might be called the ‘actuality’ and the ‘there-is’ uses respectively. Interestingly, the actuality use is said to occur not only in such propositions as ‘Socrates exists’ but, surprisingly to modern ears, in such propositions as ‘Socrates is a man’. Indeed, it occurs in any of those predicates that respond to the question ‘Quid est …..?’ (‘What is ….?), and which Aquinas calls substantial. It is in this use that ‘is’ is taken to express the being of whatever falls under the Aristotelian categories.

 

In its there-is use, ‘is’ is said to express the truth of a proposition, and to answer the question ‘An est…?’ (‘Is there any such thing as ….?’), and which Aquinas calls accidental. In these cases ‘is’ has the dual function not only of linking subject and predicate, but also of expressing the truth claim that is being made thereby.

 

As for the ambiguity of ‘is’, Aquinas' position would seem to be:

1. There is systematic ambiguity between the uses of ‘is’ to express the actuality of what falls under any of the ten categories.

2. There is no ambiguity at all between the actuality use of ‘is’ and its use in substantial predication: they are the same.

3. There is no ambiguity at all between the there-is use of ‘is’ and its use in accidental predication: they are the same.

4. There is systematic ambiguity between the actuality and the there-is senses of ‘is’, and this is founded on the supposition that the truth of what we say is founded upon the actual existence of what we talk about.
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Recap:

It’s often assumed that when we talk about things that they really do exist (in the extra-mental, or worldly, sense). For example, unicorns are things that we talk about, but that don’t really exist – not in the worldly sense of the term.

If we accept our own revisions of the things that Aristotle said about the relations of things which we talk about (if we revise his Square of Opposition and, in doing so, make it incoherent), and then we accept the unnecessary ambiguity that we’ve produced by our mis-translation of Aristotle in this way, then it “seems like” traditional logic introduces “systematic ambiguity” or an incoherence that we must then take pains to overcome by “inventing” other kinds of logics – like “modal” and “deontic” logics.

SOLUTION

My personal response to this wrong-headed thinking of Aquinas, as propagated by Barry Miller?

Numbers 2 and 3 are uncontroversial. Numbers 1 and 4 can be collapsed into an understanding that is rendered irrelevant by a return to the original wording (unpopularly championed by Abelard) of Aristotle's O – the “particular negative” – in his Square of Opposition from the contemporary misrepresentation of: "There exists some P which is not Q" to: "Not all P are Q." This return to what Aristotle got right in the first place (and what was defended by Abelard) abrogates the responsibility of checking for existential import in order to alleviate ambiguity. Indeed, Terence Parsons from UCLA has already been done this ON THE STANFORD WEBSITE! …

http://plato.stanford.edu/entries/square/ [retrieved 5 March 2008]

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This entry traces the historical development of the Square of Opposition …

 

For most of this history, logicians assumed that negative particular propositions (“Some S is not P”) are vacuously true if their subjects are empty. This validates the logical laws embodied in the diagram, and preserves the doctrine against modern criticisms. Certain additional principles (“contraposition” and “obversion”) were sometimes adopted along with the Square, and they genuinely yielded inconsistency. By the nineteenth century an inconsistent set of doctrines was widely adopted. Strawson’s 1952 attempt to rehabilitate the Square does not apply to the traditional doctrine; it does salvage the nineteenth century version but at the cost of yielding inferences that lead from truth to falsity when strung together. …

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[a paraphrased modern (non-Aristotelian; non-traditional) version of a “square of opposition”]

A … Every S is P … Universal Affirmative

E … No S is P … Universal Negative

I … Some S is P … Particular Affirmative

O … Some S is not P … Particular Negative

… Why does the traditional square need revising at all? The argument is a simple one:[2]

Suppose that ‘S’ is an empty term; it is true of nothing. Then the I form: ‘Some S is P’ is false. But then its contradictory E form: ‘No S is P’ must be true. But then the subaltern O form: ‘Some S is not P’ must be true. But that is wrong, since there aren’t any Ss. …

… Ackrill’s translation contains something a bit remarkable: Aristotle’s articulation of the O form is not the familiar ‘Some S is not P’ or one of its variants; it is rather ‘Not every S is P’. With this wording, Aristotle’s doctrine automatically escapes the modern criticism. (This holds for his views throughout De Interpretatione.[5]) For assume again that ‘S’ is an empty term, and suppose that this makes the I form ‘Some S is P’ false. Its contradictory, the E form: ‘No S is P’, is thus true, and this entails the O form in Aristotle’s formulation: ‘Not every S is P’, which must therefore be true. When the O form was worded ‘Some S is not P’ this bothered us, but with it worded ‘Not every S is P’ it seems plainly right. Recall that we are granting that ‘Every S is P’ has existential import, and so if ‘S’ is empty the A form must be false. But then ‘Not every S is P’ should be true, as Aristotle’s square requires.

[a paraphrased traditional (Aristotelian) Square of Opposition]

A … Every S is P … Universal Affirmative

E … No S is P … Universal Negative

I … Some S is P … Particular Affirmative

O … Not every S is P … Particular Negative

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On this view affirmatives have existential import, and negatives do not—a point that became elevated to a general principle in late medieval times.[6] The ancients thus did not see the incoherence of the square as formulated by Aristotle because there was no incoherence to see.

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Recap:

Don’t f#$& with Aristotle (it’ll get you creating “logical” castles in the sky).

;-)

Ed