A Problem of Logic

[Obi-Wan Nihilo]

I wonder: what if life and death are only visible from a certain perspective, rather than things intrinsic and universal?

[Zarathustra]

Mortality is our horizon, one we will actually reach.

[wayfriend]

Mortality defines us. All life is mortal, but it does not define any other life the same way, to the same degree, that it does us. Because we know we're mortal. And that knowledge is the basis of the way we live more thoroughly than, arguably, anything else.

And, as I said, there is - nothing - whatsoever - about us that suggests there might be any humans who are not mortal. Outside of fantasy/scifi, immortal humans is a contradiction; medically and psychologically.

I don't disagree with any of that. I just don't think it implies the same things you think it implies.

Yes, mortality "defines us". But that's a poetic way of saying mortality greatly informs things that humans think and do.

Let me try a counter example: a sphere is defined as "a round solid figure with every point on its surface equidistant from its center." With this definition, we can look at a ball and at a brick, and say with certainty one is a sphere and one is not, because one matches our definition and one does not.

You can also point out that spheres always roll downhill. You can point out that you cannot ever balance a vase on a sphere. You can point out that spheres only touch the ground on one point.

But do these things "define" what a sphere is? No, I would say. Just because something is always true doesn't make it a definition. These are things that are contingent on being a sphere, but are not necessary for being a sphere. Thinking hypothetically: with no gravity, a sphere won't roll down hill, but will still be a sphere; a skilled juggler may balance that vase on that sphere, and it would still be a sphere; in a curved universe, a sphere may touch the ground on several points, and it would still be a sphere.

So, the question is, is "mortal" part of the definition of human? Or is it just "always true". This is not asking about the poetic sense of informing human hearts and minds, but about the classification sense of things to check off when determining if something is human or not. And I would say, no, it does not.

At one point in time, we could say that humans are never in outer space. But when they did get into outer space, they were still human. At one point in time, we could say that humans hunted in packs. But when they stopped hunting in packs, they were still human.

Hypothetically, if we ever found way to have humans live forever, they would still be humans. Immortality is contingent, but not necessary.

What I'm getting at is that logic is flawed if it tells us we do not know that all humans are mortal; if it tells us we do not know Socrates is mortal.

Logic does not tell us what is true and what is not. That's not what it is for. Therefore, it's not failing us when it fails to do this.

Logic says, if these things are true, then these other things are true. But logic neither knows nor cares whether any of them or true.

And what happens, wf, when genetic engineering leads to humans who are not mammals? Are they still human? Will we consider them a hybrid? Lizard-men? Will we not think of them as human at all? And what about when genetic engineering leads to humans who are not mortal?

Well, that all depends on the definition of human, doesn't it? In the classification sense.

We don't actually HAVE a good definition of human. What we have is a good heuristic that helps us sort out humans from monkeys and cows and trees. Like all good heuristics, it's only good because it works on the samples one needs to apply it to. We've never had to use our heursitic on a lizard man.

A geneticist can tell you all kinds of things about human genes that are "always true". It hasn't been decided, really, if these are contingent or necessary to the definition of human.

It's not until one day we have three different genes, and we decide that one is human and one is also human and one is not, that we will have the answer. And that will be because we changed our definition produce the answer we want those samples to yield, and then everyone agrees to the new definition.

Of course, this issue is confusing because we may decide that a reptile man is not human, but we may yet consider them a person. Person and human aren't the same thing. For example, we may consider a computerized consciousness a person, but they surely aren't human in any biological sense. Or maybe we do consider them humans - it's all in how we want to define human. The definition of human will change over time, to include what we desire to include, and not include what we don't want to include. And that won't happen until we start having new samples that don't work in the current heuristic definition we use for human.

(It's ironic that the truths we observe are the truths that are most immutable, and yet are they truths we are never 100% sure about, while the truths that come from our definitions are the truths we are 100% sure about, but which are completely amenable to change.)

[Wosbald]

+JMJ+

Logic says, if these things are true, then these other things are true. But logic neither knows nor cares whether any of them or true.

Bingo. That's why the convicting power of Logic presupposes a bedrock of self-evident truth (axiomatic assumptions) or, else, it's turtles all the way down.

[Vraith]

ALL "facts" are, in the end, assumptions.

But "facts" aren't assumptions "in the end."
They are probably assumptions in the beginning...
And may remains so in the process/middle...
But not in the end.

Well, then that's where we part company. There is no contingent truth you could name, in which "to the best of my knowledge" isn't implied in the statement. This is because humans have no direct access to absolute truth. (And isn't that the kicker that makes the world what it is.)

Maybe we part, and maybe we don't. I'm not sure you read that with the emphasis I intended. I'm no fan of "absolute truth."
And it is possible that, being mortal [which may be contingent...we may well become effectively immortal through science on time scales that are beyond our ordinary comprehension---at least until we experience it---but the universe itself is most likely "mortal." We'll have to figure out how to survive or change that]---anyway, being mortal and being distinct/separate from other things [and they from us] we may never be in a position of knowing ends.
But physical facts and absolute truths are not the same game...though they have some overlap in the playing field.
It's possible [and I speculate it is so] that there are physical facts that are universal, yet are contingent---on this universe. [[they'll only be really metaversal/absolute if they are and MUST be true in every possible -verse]]

[wayfriend]

But "facts" aren't assumptions "in the end."
They are probably assumptions in the beginning...
And may remains so in the process/middle...
But not in the end.

Well, then that's where we part company. There is no contingent truth you could name, in which "to the best of my knowledge" isn't implied in the statement. This is because humans have no direct access to absolute truth. (And isn't that the kicker that makes the world what it is.)

Maybe we part, and maybe we don't. I'm not sure you read that with the emphasis I intended. I'm no fan of "absolute truth."
[...] But physical facts and absolute truths are not the same game...though they have some overlap in the playing field.

Oh dear gosh my oh f*ck. Possibly I went awry when I used the term "absolute truth". What I meant was "absolute certainty". That is, there are no facts that we know with absolute certainty, and that we have no direct access to a "perfect knowledge" that provides absolute certainty about contingent truths. (As opposed to necessary truths, which, because they arise from our own definitions, we do have absolute certainty - but that certainty is of trivial value.)

"Absolute Truth" means something else entirely, by it's accepted definition. The argument is con-fused enough without adding that!

[Obi-Wan Nihilo]

WF is killing it in this thread.

[Zarathustra]

WF is killing it in this thread.

Aside from 4 or 5 patently false statements, he's not doing too bad.

What I'm getting at is that logic is flawed if it tells us we do not know that all humans are mortal; if it tells us we do not know Socrates is mortal.

As WF says, that's not what logic is "for." Logic deals with relations of ideas, the formal structures that connect them. Whether or not humans are mortal is a matter of fact. Facts are contingent, never necessary. Only relations of ideas can be logically necessary.

It's incorrect, however, to say that logically necessary connections between ideas are trivial. Mathematics, for instance, is not trivial. But true mathematical propositions are necessarily true.

... mathematical statements are a posteriori synthetic statements of a very special sort, because they do not depend on the contingent features of the empirical world, but rather are logically necessary properties of the mathematical structures realized or potentially realized in the empirical world (as shown by the invariance of these properties under isomorphism).
Moreover, even though they are synthetic statements, they resemble analytic statements in being logical consequences of the axiomatic definition of the mathematical structure they are dealing with. For this reason, we have proposed the term structure-analytic statements to describe them.

Their logical status as structure-analytic statements gives them a logical position intermediate between truly analytic statements and ordinary empirical statements. This explains the nontrivial and nontautological character of many important mathematical theorems, which often gives them the quality of a priori quite unexpected “brute facts.” This is an aspect of mathematics very hard to explain on the logical positivist assumption that mathematical statements are truly analytic.

link.springer.com/article/10.1007%2FBF00174780

[Fist and Faith]

So the question is, is "mortal" part of the definition of human? Or is it just "always true". This is not asking about the poetic sense of informing human hearts and minds, but about the classification sense of things to check off when determining if something is human or not. And I would say, no, it does not.

This is, indeed, the big question. And, obviously, I answer the opposite way.

There are different categories of things, and different categories of characteristics that make up the definitions of things. Not all categories of characteristics are part of the definition of all categories of things. (I hope I wrote those two sentences well enough to be understood. Heh)
-Characteristics of life are not part of the definition of spheres.
-Characteristics of food production are not part of the definition of fungi.
-Characteristics of locomotion are not part of the definition of trees.
-Many significant characteristics of the psyche are not part of the definition of birds. We possibly agree that the psyche doesn't play any part in the definition of birds.

Humans are unique. Nothing else we're aware of comes close to us in awareness, intelligence, emotions. Our mind is, as they say, orders of magnitude more complex than the mind of anything else that has any mind at all. To attempt to define human without the mind seems a preposterous thing to me. It is the thing that most truly distinguishes us from everything else we are aware of.

Our psyche (By which I mean the non-intellectual aspects of the mind. Hope, fear, desire, love, hate...) is likewise far more complex than the psyche of anything else. My own opinion is that, in general, we act on the psyche more than we do on the intellect. Wars are not fought because we cannot intellectually solve the world's problems. We can solve them with our intellect. But we don't. Instead, we go to war over women, or envy, or a million other stupid things, and blame it on an inability to solve problems.

When Bill Clinton was POTUS, he acted on feelings of lust and power, when an intellectual examination of what he was about to do would have told any idiot that he had immeasurably more important things to do, and the most watched person on the planet could not possibly expect to do such a thing and not get caught.

There is vastly more news about the Kardashians, sports, and music than anything intellectual.

Our psyche rules us, and it is a huge part of what sets us apart from everything else. I say it is the most important part of the definition of human. And our psyche is shaped as much by our mortality as it is by anything else. If we found beings who looked exactly like us, and we could not tell them from us no matter how many physical examinations and tests we ran, but they were immortal (whether the get in a regeneration thank every year; are bathed in special radiation from some star; are favored by some powerful being; whatever), we would be able to distinguish them from us by the differences in how we view life and reality; the things that are important to us; the societies we form; etc.

[Zarathustra]

In one sense WF is right, in another FF is right. But neither of you are using the language and concepts of predicate logic to make your distinctions--the actual terminology that professional philosophers use to avoid the confusions rampant in this thread.

A "textbook" definition of human beings is going to treat us like other organisms, other mammals, other primates. We have a classification, a species name, and certain biological attributes (in terms of logic, these would be called predicates). Mortality wouldn't be listed since it's simply a given for all organisms. It would be like listing "life" as one of our characteristics. But we're talking about a living creature, so of course we're alive. And of course we'll die. It's not an attribute or a predicate, it's an existential structure of our being.

But that "classification" in terms of predicates would miss much of what is distinctly human about us ... and it's not just poetic [it's part of logic ... there are symbols in predicate logic for being and not-being ... see below]. As FF notes, our minds are much more sophisticated. This is a biological fact, a logical predicate. And with this increased knowledge comes the knowledge of our mortality.

It's very likely that we're one of the few creatures on earth who are aware of our mortality on a level higher than instinct. It's not just that we avoid predators and high falls, but that we have this existential crisis looming in our future. We--alone of all creatures--can choose to die. Camus calls it the "first question" of philosophy: why not suicide? Thus, we're also the only creatures who can make a conscious decision to live, aside from a survival instinct. This is uniquely and "definitively" human.

But as I said, it's not a logical predicate or attribute, it's an existential structure which acts as our "horizon of being." It's the limit of our finitude. It's a condition of our being, a context through which all our choices are made (either explicitly or implicitly ... we can be authentic or inauthentic in relation to that knowledge).

"Not-being" (i.e. death) is no more a predicate than being itself is a predicate. Being is the condition or possibility of having predicates. "Not being" is the impossibility of having predicates. You're making a logical error, FF, a categorical error, that is similar to the main fallacy of the ontological argument for God's existence, pointed out by Kant. In formal logic, being (and thus not-being) even has a different type of symbol. Existential quantifiers are different from predicate variables.

[wayfriend]

There are different categories of things, and different categories of characteristics that make up the definitions of things.

Absolutely. A geneticist would define "human" in one way. A biologist in another way. A neuroscientist another. A lawyer yet another. It all depends on what aspect of human- nature they are focusing on, I would say.

But I also know that when I walk down the street, I don't pick out the humans by testing their DNA, or electro-probing their brain. So there's yet another way involved here.

Our psyche rules us, and it is a huge part of what sets us apart from everything else. I say it is the most important part of the definition of human.

I don't disagree. But (new topic, not rebuttal) we all must be aware of the dangers of being too specific. For example, you can define a human as a creature that walks upright on two legs ... but this permits us to exclude people confined to wheelchairs if we are not careful. Yes, that is a reductio ad absurdum. But humans by and large have been unkind to those we consider not human, so it's worth thinking carefully. It's inevitable that progress will lead to new ways to be human. When we tinker with our own genes, will geneticists still say we're human? When we augment our minds with computers, will neuro-scientists still say we're human? When we control our emotions and our instincts as easily as we control our hair color, will our psyches be what they are now? When these things happen, we either need to be willing to change what we consider to be human, or live with the consequences of labeling people non-human. (And it's not a "given" that the non-humans will be the losers in that split.)

[Fist and Faith]

Yeah, I really left the intent of the thread a few posts back. Heh. Sorry. I should make a "Definition of Human" thread.

[Obi-Wan Nihilo]

Mortality is our horizon, one we will actually reach.

I disagree. For how can one ever experience the cessation of the functions that enable experience itself, without also positing an immortal soul that renders the question moot?

[Zarathustra]

Doc, you make fair, interesting, and nontrivial point. However, it's possible to experience dying, at least, if not death. So it's something we do have to face, especially since "reaching" that terminal point can be understood in a sense other than experiencing it. We get there, whether we know it or not--unlike the literal horizon, which is impossible to ever reach. That was the image/metaphor I was going for. (I suppose that's the trouble with being "poetic" about death. )

[Obi-Wan Nihilo]

Z., wouldn't you also say that we overestimate the resemblance of our concepts of life, death, and humanity with the things-in-themselves (including us). It seems to me that there is a fair amount of abstraction and perhaps even oversimplification within each of those terms. I think the things that constitute the categories of life and humanity are fuzzier and less coherent than we'd like to imagine. And at some level these qualities become illusory, given the apparently fundamental unity of all experience.

[Avatar]

It's our nature to anthropomorphise things.

--A

[Fist and Faith]

Mortality is our horizon, one we will actually reach.

I disagree. For how can one ever experience the cessation of the functions that enable experience itself, without also positing an immortal soul that renders the question moot?

To me, the most important thing is that we live mortal lives. We live knowing that, one day, we won't.

[Obi-Wan Nihilo]

Yes, but is that realization merely trivial and personal, or transcendent? Or is there a way in which it is all three?

[Fist and Faith]

Different individuals react in different ways. As a species, it's difficult to imagine anything having a stronger influence. It's one of the things that makes up the soil that our collective consciousness grew from.

[Vraith]

Yes, but is that realization merely trivial and personal, or transcendent? Or is there a way in which it is all three?

Not just a way, but several, that it can be all three.


Anyway, this is a book that was suggested too me, that I might get, that is somewhat relevant to the OP.
Blurb from Amazon. Emphasis mine.

Challenging the hyperspecialized epistemology of modern philosophy in the West, Barry Allen urges his readers toward an ethical appreciation of why knowledge is worth pursuing.

Western philosophers have long maintained that true knowledge is the best knowledge. Chinese thinkers, by contrast, have emphasized not the essence of knowing but the purpose. Ideas of truth play no part in their understanding of what the best knowledge is: knowledge is not deduced from principles or reducible to a theory. Rather, in Chinese tradition knowledge is expressed through wu wei, literally “not doing”―a response to circumstances that is at once effortless and effective. This type of knowledge perceives the evolution of circumstances from an early point, when its course can still be changed, provided one has the wisdom to grasp the opportunity.

www.amazon.com/dp/0674335910/ref=rdr_ext_tmb