I realized that some programming languages employ the concept of universals. A class is a universal definition for a group of objects that have the same kinds of properties and behavior. Once you define a class, you can create objects with particular properties as defined by the class.

In fact, the behavior (the functions each object can perform) lives in the class. All objects share the same behavior by virtue of the class.

And indeed, introductions to this kind of programming often use Dog and Cat as two different classes, and go on by saying that this style of programming models the real world. This kind of programming came into existence with a language focused on simulation.

What this shows is that at the very least, the concept of a universal is meaningful and coherent. Whether it is when applied to the world is the question. But certainly we possess universal concepts.

Again, if you're asking a psychological question, it's meaningful. What other question you might be asking, I can't understand. — Snakes Alive

I'm asking what allows for individual things in the world to have the same properties. How is that not meaningful?

Nothing. We can't. It's just one way of looking at things. — Pseudonym

Then I'll assume Carnap's argument is itself meaningless. Isn't it a metaphysical argument?

If you can't articulate the question meaningfully, then Carnap (and anyone else) is licensed to ignore it. It's your job to frame a question meaningfully: otherwise, the demand that others answer it doesn't make sense either. — Snakes Alive

But what gave rise to the question of universals remains. Carnap and others might take issue with the meaningfulness of the universal concept, but there is still a matter of how particulars can have the same properties such that we can categorize them.

This is a psychological question, and meaningful. But I don't see what it has to do with the existence of universals. — Snakes Alive

It could be psychological, and that would be conceptualism. But now you've taken a step toward the debate being meaningful.

The realist would ask how individuals have the same properties. Unless this can be answered by some other means, the realist can just say that universals have to exist to explain that fact. But if you answer the realist, then you've conceded that the debate is meaningful.

Carnap would say that realists, conceptualists and nominalists are wasting their time trying to answer a question without meaning. But shouldn't Carnap have to account for similarity?

The parallel was intentional: you said a universal was that which explained some fact. But simply introducing something as that which explains something else makes no sense, because introduced ex nihilo in this way it does no actual explaining, and so I don't know what it is I'm supposed to be arguing about. — Snakes Alive

A universal is meant to explain the discrepancy between a world of individuals, and the huge amount of categorization we perform.

If it's a tiger, it's a tiger. What's meant by "being a member of the tiger group" other than being a tiger? Are you asking me what makes it so that if something is a tiger, it's a tiger? — Snakes Alive

How is it that we have the concept of categories when the world we perceive is individual? Nobody ever perceives a tiger in the categorical sense. They perceive animals that are similar. What is it about the similarities that allows us to categorize?

"There are tigers. A flyger is that which explains this fact. Are there flygers? — Snakes Alive

But flygers hasn't been defined. So what makes an individual tiger a member of the tiger group? If it's not a universal, then what is it? I'm asking because if universals don't make sense to you, then how do you make sense of individuals having the same properties? Is it just a brute fact of existence?

I don't know what that means, because I don't know what it means for two things to have something in common "in virtue of" some third thing (or not). — Snakes Alive

By that do you mean you don't know what natural mechanism would allow for such a thing, or do you mean the concept really doesn't make sense?

If it doesn't make sense, then what do you think it means for individuals to have properties "in common"? Are they the same properties?

I simply don't understand the question. I know what it means for a dragon to exist (or not); I don't know what it means for a universal to exist (or not). — Snakes Alive

Well, I've tried to provide a pseudo-argument for what a universal means.

We can pick on universals. Do any of the following statements contain an appeal to emotion? It's not a formal argument.

We perceive individual things.
These individual things have similarities.
The similarities allow us to categorize the individuals.
Categorization is evidence of something the individuals within a category share.
This something explains how individuals have similarities.
This is called a universal.

You don't have to agree with the above pseudo-argument. This is a question fo whether it's meaningful (intelligible).

But this is begging the question. Carnap proposes that arguments for various metaphysical positions are irrational and you respond by saying that they are. What Carnap is really pointing to is how can you prove that they are? — Pseudonym

The form and validity of each step in an argument, I suppose? Don't we have a criteria for what structure a logical argument takes? It's true that often arguments are presented in ordinary language without the rigid logical structure, or to elaborate on the premises and steps in the argument.

But let's say for sake of argument that we can't tell what a logical argument is. What makes Carnap's argument logical and not irrational? How can we prove that Carnap is right?

I think some people are sociopaths and don't feel empathy, because that's how their brains formed. Other people might feel empathy, but they're emotionally scarred, or are able to justify their actions to themselves. We can all be selfish, get unreasonable angry, have irrational fear, etc. And if you're raised in an environment where you have to learn certain survival strategies, like street smarts or being tough, then that can overrule empathetic concerns.

'how would our experience of a world in which only matter exists differ from one in which only minds exist?' or 'how would my experience of a world in which only I exist differ from one in which other minds also exist?' — andrewk

But only if you limit the discussion to your 'experience of'.

'I tend to agree with Carnap that questions of ontology have no rational meaning. — andrewk

I don't see how this is possible since many people have made rational arguments for various metaphysical positions.

But those questions, especially the second one, are very emotionally meaningful to many people. — andrewk

I'm not emotionally attached to every metaphysical argument, but I can make sense of some of the ones I don't particularly care about. It doesn't really matter to my life whether universals are real, but it's interesting to think about sometimes, just like it's interesting to wonder whether the laws of physics really 'break down' inside a black hole, which is just as meaningful, except for the difficult math.

But as to the existence of universals, I can't make any sense of the question — Snakes Alive

As I understand it, universals come about by observing two aspects of the world we perceive:

1. The distinctiveness of things, thus particulars.
2. The similarities between particulars allowing us to categorize the world.

The question that arise is by virtue of what do individual things have the same properties? Sharing a universal object that has those properties is one possible answer. The realists would say that is by universals that we're able to categorize the world. Apples all share the same apple universal, thus making them apples. Otherwise, how would we put a bunch of individuals into the apple category?

It is a problematic concept, and it's easy to think that our minds are creating those universal categories, as opposed to them existing in nature. But that still leaves the matter of similarity.

At any rate, this isn't an argument for universals, only that I think it's meaningful one. Can you explain how you can't make sense of it.

If we were to take time travel as a process of reversing the universe's history while the time traveller stays within a bubble for instance, in a manner similar to rewinding a cassette tape, then everything stays within a single 3D universe and we can visit 1850 and kill out ancestors without problem. — Mr Bee

I guess, if there was a mechanism for rewinding* the universe. One could be invented for a story. Surely there must be some stories out there with this. I can only recall stories about visiting existent future or past points in time, or parallel timelines. The ones involving the same timeline often allow changes from the past to ripple forward to the present (or future) somehow. Star Trek time travel was portrayed that way.

* Actually, Thanos and Dr. Strange did the rewinding events thing in the Marvel movies. It was on a local scale, though. But that would support presentism in those stories, except I think the comics have the other forms of time travel as well.

Anyway, the point of these time travel stories is that we can make a meaningful distinction between the different notions of time, and if physics/technology allowed us to, we could time travel in a similar fashion, depending on which view of time is true.

Why not? We travel forward in time, obviously, and that makes perfect sense. We also can orient and move in space in any directions, and space is just as "abstract" as time, isn't it? — SophistiCat

On a certain view of time, the present is all that exists. Time is simply the world undergoing change. As such, it would be impossible to construct a wormhole or whatever to jump to a previous or future point in time, since neither exists. I believe this is a version of the A-series notion of time, or presentism. I don't know how that's made consistent with Relativity, but I guess some of the concepts of spacetime in GR are rejected (replaced by presentist concepts), although not the experimental results.

HG Wells The Time Machine could not be written under a presentist view of time. A machine can't be traveling from the future to kill Sarah Conner or her son, and there is no parallel timeline/universe for Donnie Darko to save his family from the end of the world (or whatever he was doing).

That's what you get when the colonized west makes a blockbuster Hollywood movie about what an uncolinized Africa would be like. — Noble Dust

Was uncolonized Africa that much different than the rest of the world? There have been plenty of empires and conquest from many different civilizations and groups prior to European colonization.

He was the voice of pain and anger that the movie had to provide, but they avoided condoning his aggression by making him a villain. — Fool

Well, he did want to basically use Wakunda's advanced tech to start a world war to get back at the world for colonialism and slavery. It would have been bad for everyone, Wakanda included, as Black Panther noted. Some of those other nations do have nukes, and large military forces.

The universe will chug along? What does that mean? — Metaphysician Undercover

That the universe is a choo choo train. Thought everyone was undoubtedly certain of this?

I'm not an idealist. Just pointing out that philosophical certainty is very rigorous. I agree that the sun will come up tomorrow, you're not a BIV, we will all die, and the universe will chug along just fine without perception.

Idealists die don't they? — Cavacava

I think so. Berkeley's not still among us. Maybe God grew tired of perceiving him?

What is the difference between the phenomenal that we sense, and what the BIV senses...? I don't see what's different so then what is the use of a distinction where there is no distinction. — Cavacava

For the idealist, none. Not everyone is an idealist, so ...

BIV....if it is a perfect simulation then how would it make any difference, and if it does not make a difference then what good is the notion. — Cavacava

It matters for the whole idealism/realism/skepticism argument. The skeptic would say that if the perfect BIV scenario is possible, then our claims to knowledge are wrong, since we can't be certain we're not perfectly envatted. The idealist would respond by saying we know what appears to us, and the BIV scenario could only exist for the mad scientist. And the realist would be left with the difficult task of bridging the epistemological gap.

We can certainly say who cares, it doesn't matter, nobody really acts like solipsism is true, etc. But it doesn't change the fact that these are well established philosophical problems. And that was enough to plague Witty throughout his life, or so I've read.

If it makes no difference in our lives, it isn't fit material for philosophy. — Bitter Crank

It was fit for Hume, Kant and many other philosophers, starting with the ancient skeptics. I don't delve into philosophy because it's practical, I delve into it because it's about the big questions we all wonder about.

I don't take the simulation or BIV argument seriously in everyday life, because they're made up scenarios based on our current level of limited technology, but I do sometimes wonder about appearances versus reality, which is more generally the Kantian concern, and is backed to some extent by the findings in science the past several centuries, particularly physics.

However, if we ever do get to an advanced enough technological level, then some of Bostrom's arguments take on more weight. One Star Trek Next Generation episode involving the infamous Holodeck malfunction ended with the crew pondering whether they were inside a simulation of someone else's construction. And if you have that level of technology, then it does become a real concern.

One in 60,000 is just to close for comfort. (You face higher odds of dying from other things that you continue doing, because your attitude allows you to.) — Bitter Crank

Sure, but this isn't the same thing as philosophical certainty. When we want to know if we're certain the sun rises tomorrow, we're not concerned about our feelings on the matter. Rather, we're concerned about knowledge claims. Can anything outside of logic or math be certain?

Example: I don't think I live inside a simulation of some sort, and it doesn't effect me in everyday life, but can I know that for sure? Is there a defeater for the simulation argument?

So it's not "Can we be certain that the sun will rise tomorrow?" but "Ought we be certain that the sun will rise tomorrow?" — Banno

In a sense, you're right. But if an astronomer were trying to asses the probability of the sun shining tomorrow, they would take into account the possibility of a black hole wondering into it's path, or whatever might result in it not shining 24 hours from now.

A physicists might say there's a non-zero chance all the atoms of the sun don't fuse tomorrow, or release their radiation until 48 hours, or pass through one another, missing the nucleus or what have you.

I used to subscribe to the singularity movement where many things will happen at once when AI arrives on stage; but, my personal opinion is that it might take longer than an instant for things to change. — Posty McPostface

The longer it takes, the better. A hard takeoff singularity is probably disastrous, as they're no way human society can adapt that quickly, and you end up with powerful technologies run amok. There's plenty of dystopian fiction exploring that sort of thing, and the friendly AI movement hopes the proper precautions are in place before we have general purpose AIs.

I also think we will likely become a multiplanetary species within the next decade or more. — Posty McPostface

I have my doubts. Mars is less hospital than the center of Antartica in the middle of the winter, and it's much farther away. That makes it very expensive and risky, and for what? To have a dozen or so humans call it home? They will be confined indoors on inside a suit at all times.

Exploring Mars with better robots and at some point human beings, sure. But living there? Maybe in the long, long run when we can terraform the planet.

How do you think changes will occur, or what is your conception about the future as you see it? — Posty McPostface

People at the turn of 20th century were similarly optimistic, then we had two world wars, a nuclear arms race, and wide spread environmental concerns. We could still have WW3, and an environmental collapse is a definite possibility.

That being said, I'm more on the optimistic than pessimistic side about human civilization persisting and advancing, despite whatever difficulties the 21st century holds. But we really don't know whether civilization is inherently unstable and always leads to collapse, no matter the level of technology. It has so with all past human civilizations. We don't anything know about alien ones, if they're out there. But one possible resolution to the Fermi paradox is that civilizations don't last, or there's a great filter ahead for us.

Or maybe when we achieve a post-singularity world, they'll welcome us into the galactic club. However, imagine what a post-singularity world war would look like. Weaponized AI, gray goo, antimatter bombs, super virues, and I'm sure nukes can still have their place.

As I see it, phenomenalistic/subjective idealism faces three challenges:
1) Avoid the collapse to solipsism
2) Account for the apparent permance of particulars
3) Account for the apparent fact that numerically distinct people can perceive one and the same thing in different ways (i.e. from different perspectives). — MetaphysicsNow

I hadn't thought of number two. Regarding #1, idealists had attempted to dismiss it with the claim that idealism includes other minds from the start. The problem there is epistemological. How do they know about the other minds? And that leads to a justification issue. You can't just define other minds into existence and call that good.

I've seen at least one hard core idealist admit that #3 was a challenge. I don't recall seeing mention of #2, but it's definitely an issue. I think there were claims that each perception was a separate particular, and there was no permanence. Problem being that we do perceive objects persisting.

Whether you can have Berkelian idealism without also requiring God to be around in the quad is an interesting question. — MetaphysicsNow

We definitely have posters who have argued for subjective idealism without utilizing God, even saying that God was the flaw in Berkley's philosophy.

dealing with issues concerning nominalism v realism about properties , personal identity over time, adverbialism and representationalsim in the philosophy of mind, to name just a few. — MetaphysicsNow

Sounds interesting. I've wondered if there is a way to resolve fundamental metaphysical disputes with that sort of approach where you bring in the various related issues and try to tie them all together.

o have a role for God in the sustaining of the Universe. An earlier contributor is quite right to bring in quantum mechanics where the issue of non measurement comes to the fore as having an influence on events. — Edmund

Can a supernatural being perform a measurement? Is God collapsing the universal wave function to this universe, allowing us to evolve?

> For all these things I just mentioned, I see no better than the blind

For some reason, vision is often abused in philosophy as the stand-in for all perception and observation. Thing is that vision works differently than smell, where you're inhaling pieces of the thing itself.

> I only see the surface of the same side when I look at the moon, what are you guys looking at? I might as well ask if what's below the surface of the Earth actually exists because I don't look at it. Does my brain exist, heart, lungs, bones, etc

Indirect observation has been brought up several times in this thread. The moon's gravitational influence continues when we're not looking at it, and our bodies do all the body-things like pumping blood, breathing and digesting (or having thoughts) while we're not looking inside.

I take that as evidence that a naive form of idealism is no more tenable than naive realism.

Why is inherently selfish bad? — schopenhauer1

Selfishness is only bad when it harms others. Since we're social animals, and survival is a social matter involving a fair amount of reciprocation, selfishness is seen as a negative trait.

But if we were intelligent felines, it probably wouldn't matter.

Because pleasure isn't an intrinsic but an instrumental good and therefore inherently selfish. — Thorongil

So you're no hedonist. Does that mean hedonists would necessarily disagree with antinatalism, or only if pleasure outweighed the pain of being alive?

I am not advocating going backwards in time. I am just pointing to our ignorance and how beholden we are to larger forces we had no hand in and did not create ourselves but certainly dictate modern life for us. I can't explain its significance more than there is an alienation or atomization to this. — schopenhauer1

I see. Well, it might get worse if AI becomes more generalized in capability.

The point of my post was to address the fact that we are mostly ignorant of the very processes and things we take utilize in daily life. We become passive participants and eventually become beholden to the given which is: — schopenhauer1

Yes, and maybe there is something less than good about that. Thus the DIY movement, and all those shows about how STUFF gets made. But is it worse than what we had before?

Maybe a smith would know everything about how an object was made. Was their life better off overall?

Would I do a better job of providing all of these requirements myself? Emphatically no! I cannot be an expert in everything. — Shatter

Indeed! Specialization (along with automation) has allowed the standard of living to go way up, for all of us unfortunate souls who get to be alienated. Not saying it's a perfect result, but I would say it's generally less bad than what came before.

Although I have no idea what life was a hunter/gatherer would be like, but at least with civilization, the standard of living is much better now, for those who have access.

Now the burden is to show when things weren't bad, and why they weren't, and how we can maybe fix that. It's easy to decry things. It's very hard to explain how to make things better. — csalisbury

Indeed. If not being alienated from production means slaving away on a farm to make ends meet, I probably would rather be alienated with all my consumer goods, unless I'm really into farming.

Let's not kid ourselves. Before capitalism there was feudalism, and that was not better for most people, despite there being a lot less alienation with production. And there are still parts of the world where people have to produce their own goods. They tend to be rather poor, and many of them would rather have access to the alienated labor and goods.

If being alienated means I have clean drinking water, abundance of food choices, access to healthcare, education, travel, etc. then that's magnitudes better than most humans had before me.

"If this interpretation of the data is correct, then aging is a natural process that can be reduced to nanoscale thermal physics—and not a disease" — StreetlightX

But there are some organisms that don't age, and our reproductive cell line is immortal and doesn't age. So aging is not necessary, at least for some types of cells, and there is ongoing research showing some promise into slowing or even stopping the aging process in various animals, including humans.

Over the last few years, machine learning has taken off. It's not new, but the data and processing power available reached a threshold where it started to give good enough results for everyone to jump on board.

The VR/AR stuff is seeing some commercial adoption. Someone already mentioned self-driving cars, although they're still in the testing phase, so that puts them behind VR. Big Data has been rather influential. Progress is being made on quantum computing.

It's probably a matter of when certain highly visible technologies gain widespread adoption, even though they existed in some form for years before then.

However, I'm not convinced that technology has been accelerating the past several decades compared to the late 18th century though the middle of the 20th. I think it has slowed down a bit, relatively speaking. At least as far as big transforming technologies go. We have computers, the internet and cell phones. They had electricity, automobiles, aircraft, vaccines, major breakthroughs in physics, etc.