What do you mean by "quantifiable"? I'd simply say that there's no item of knowledge to which knowledge of it is infallible, therefore we don't really possess certainty in this maximal, philosophical sense. We can debate some phenomenological stuff, but even logic and mathematics gets affected by this.

In a colloquial sense, it's just probability. You claim it begs the question, but it really doesn't. The average Joe (myself included), in every day speech, is liable to say that when he's "certain" or "uncertain", he's simply communicating the rough likelihood of something he believes or knows to be the case. It's just a substitution of terms in that case, so I don't see where the question begging enters.

But something can be highly probable and people can feel uncertain about it. Conversely, people can feel certain about the most improbable things.

Is it merely a feeling or is it quantifiable? — Purple Pond

The first thing to note is that certainty is an attitude.

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?"

The first thing to note is that certainty is an attitude. — Banno

Not sure about that, but I would say that it is a state of being.

Certainty being a real, true state and uncertainty an unknown or unproven state.

I would say that it is a state of being. — Sir2u

What is a state of being?

I can make sense of a propositional attitude, but a state of being - sounds suspicious.

uncertainty an unknown or unproven state. — Sir2u

Folk are certain of unproven things all the time. So that's not right.

That's because certainty is an attitude.

I think there is a distinction to be made between certitude, which is an attitude, and certainty, which is an undoubted fact.

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.

Certainty means that your certitude is a definite fact.

I agree that

The first thing to note is that certainty is an attitude. — Banno

because a calculation that demonstrates that something is very likely or unlikely to happen provides little comfort in itself. Let's say that a stadium holding 60,000 fans will be hosting the last game of a tied World Series. You have a ticket, and you definitely plan on being there. The morning of the game a terrorist organization announces that 1 (one) person will be selected randomly and will be killed during the game--shot; instant death. No suffering.

Will you still attend?

1 out of 60,000.

Your decision to attend or not attend is a question of emotion and attitude, more than probability, because the probability of you being killed at the game is low. If you go, it will be because you FEEL confident that you won't be the one. The probability of dying at the game, you tell your self, is really, really low. If you don't go, it will be because you FEEL there is too much risk of you BEING THE ONE. 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.)

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?

The problem is that we use the word "certainty" to refer to things which are known as definite fact, while we use certitude to refer to the attitude of an individual being certain. I can say that It is a certainty that Donald Trump is president of the United States, and I can express the same thing as a certitude, by saying that I am certain that Donald Trump is president of the United States. The two propositions "it is certain that...", and "I am certain that..." have distinct meanings.

The op raises questions about "certainty", and if there is such a thing a certainty. If you argue to reduce all certainty to the attitude of certitude, then you argue that "certainty" as we commonly use it doesn't refer to anything real. But then the op goes on to question "uncertainty". And "uncertainty" is generally used to refer to an attitude like certitude, so it would be a mistake to represent "uncertainty" as the opposite of "certainty".

If you argue to reduce all certainty to the attitude of certitude, then you argue that "certainty" as we commonly use it doesn't refer to anything real. — Metaphysician Undercover

There are, as a great philosopher said, "known knowns, known unknowns, and unknown unknowns."

We can sort things into those three categories.

known knowns:

sun rises
ice melts at >0ºC
bolts of lightning cause thunder

known unknowns:

One of 20 horses will win the Kentucky Derby (which one?)
One fine day I will drop dead (which day?)
Frost may ruin the apple crop (where?)

Unknown unknowns:

All the things that might happen about which we have nary a clue even existing. Even though unknown unknowns make themselves altogether too well known all too often, we can't guess what future unknown unknowns will be.

We can have certainty about known knowns; there can be some doubt about known unknowns, but considerable certainty as well. We can also be fairly certain that unknown unknowns will make themselves known in the future.

Claiming that we can't be certain about the sun rising is posturing. Is anyone really uncertain that ice will melt a temperature greater than 0ºC? Does anyone actually think that all of the horses in the KY Derby will either break their legs before they reach the finish line, or that 3 to 20 will arrive at exactly the same moment? Does anybody believe that nothing totally unexpected will happen in the future? No, they don't.

Nobody thinks they are a brain in a vat. Nobody things they are actually a character in a simulation. These are interesting mind games, but games none the less.

Can anything outside of logic or math be certain? — Marchesk

Practically, yes. We can't be certain about everything, but there are many things that we are certain of--like the sun rising and that we are not brains in a barrel.

I would take the question about rising suns or barrels of brains seriously if I thought you did. Your only concern about the sun rising is coming up with a proof. The sun will rise whether you come up with a proof or not, because your proof is irrelevant. So would mine, so would everybody else.

If it makes no difference in our lives, it isn't fit material for philosophy. It's like "Can angels dance on the head of a pin, and how many?" It's utterly irrelevant.

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.

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.

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.

This post is based on topic "uncertainty". All the readers posted views are really admirable. Keep it up.

Unknown unknowns:

All the things that might happen about which we have nary a clue even existing. — Bitter Crank

Actually, the category of unknown unknowns is quite difficult, and somewhat paradoxical. You can't name any unknown unknowns because that would say that they are known as unknown. Even to say that there is such a thing as unknown unknowns is to say that it is known that there are unknown unknowns and that's paradoxical.

Claiming that we can't be certain about the sun rising is posturing. Is anyone really uncertain that ice will melt a temperature greater than 0ºC? Does anyone actually think that all of the horses in the KY Derby will either break their legs before they reach the finish line, or that 3 to 20 will arrive at exactly the same moment? Does anybody believe that nothing totally unexpected will happen in the future? No, they don't. — Bitter Crank

I think the issue is whether the fact that ice will melt at temperatures above 0 degrees is really anything more than just the attitude of individuals who believe this. If this fact is reducible to just a whole bunch of people believing this, the certitude of all these individuals, then there is no such thing as "it is certain that ice will melt above 0 degrees". But if there is something independent from the individuals who believe this, which constitutes the fact that ice will melt at temperatures above 0 degrees, then we have an objective certainty. It is certain that ice will melt at temperatures above 0 zero degrees, regardless of the beliefs or certitude of any individual human beings. We use "certainty" as if it is an independent, objective thing, but maybe it's just an attitude and there is no such thing.

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.

Old school. We can't know any empirical claim with 100% certainty, isn't that what Kant showed, that the Noumea is not something we can know.

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.

p.s. take the blue pill.

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 ...

Idealists die don't they?

Idealists die don't they? — Cavacava

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

Uncertainty is simply a gap in our knowledge. There are many reasons for that situation.

It could be that our mind's aren't capable of processing the amount of information required to achieve certainty. An extreme case would be the impossibility of omniscience for finite beings like us. There's just too much stuff to know.

May be the uncertainty is imposed from the outside in contrast to what I said above. We may not have the instruments or they may be inaccurate leading to errors in our predictions.

Also what if certainty is simply impossible to achieve. This seems to be the case with me. How can one ever be sure that what we know is the truth. There's time to consider. What if what we know is only a temporary state of the world? There's space to consider. What if what we know is confined to our Earth, our Solar system and that the rules/laws are totally different in other parts of the universe? The bigger question is how do we know if all this is not an illusion? These are unanswerable questions which leads to the fact that uncertainty is what we have to live with.

Given this is the case we stratify our world. One obvious classification would be to physical and mental. We can increase the certainty in our knowledge of the physical world with greater ease than in the mental world. We can have better instruments and unbiased data, etc. We can play around with the level of certainty we want in knowledge - 70%, 80%. 90%. 99%.

Uncertainty is inescapable but levels of certainty can be achieved.

Well if so then thought must be contingent since the good Bishop is not still here, and there must be a here, where they are no longer at and therefore a reality that is independent of their dreams.

Uncertainty is the knowledge that our predictions can fail. "Certainty"/"Uncertainty" seems to be one of those philosophical buzz-words that has evolved into meaninglessness. There is no "certainty"/"uncertainty". There are only predictions which can be wrong or not. We live in our predictions. Our world view is made up of predictions.

So then the only certainty is contingency whose only limit is possibility.

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.

I'm not sure.

We can play around with the level of certainty we want in knowledge - 70%, 80%. 90%. 99%.

Uncertainty is inescapable but levels of certainty can be achieved. — TheMadFool

How would you be certain that the level of 70%, 80%, or 90% had been achieved? Or would you be 90% certain that 70% certainty had been achieved, etc.?

and the universe will chug along just fine without perception. — Marchesk

The universe will chug along? What does that mean?

How would you be certain that the level of 70%, 80%, or 90% had been achieved? Or would you be 90% certain that 70% certainty had been achieved, etc.? — Metaphysician Undercover

I guess we'd have to look at our instruments. A measuring scale with an error margin of +/-1% would mean we're 99% sure. Right?

No, because the margin of error is an average, so it doesn't mean that each time is 99% sure.. And there could be other factors involved which are not being measured.