Aspirin makes the world disappear. — frank

No. But consider Descartes sat before the fire with his ball of wax; fourth meditation, expounding upon how intellect, rather than the senses or imagination, is the primary way in which we understand physical objects. Had he stuck his hand in the fire, he would have discovered something prior to cogito. Pain!

Okay, but do you have an argument for your conclusion? Are we no longer capable of induction in the 21st century? Was Aristotle wrong that we should have wide experience before drawing conclusions? — Leontiskos

Aristotle was not wrong in his time.

But neither he nor we can make induction a valid move that secures knowledge.

I say he wasn't wrong because I can see how his inferences are good given his circumstances, influences, and concerns not just from the rest of his writing but also from others' writings at the time, as well as writings about those writings.

But I don't think we can travel by induction up to knowledge of God, for instance. I'd say there is a limit of some kind on our ability to judge on some questions we might want to answer or try to answer, but don't seem like we can reliably answer.

Because the idea that such a process is defeated if we do not consider every single scientific claim that exists or is available in our linguistic context looks like a strawman. Even if we don't look at every single scientific claim, the process is still perfectly sound. And the person who looks at more evidence will be more suited to draw conclusions. — Leontiskos

I'm not sure that the process is sound. If we don't check every member of a set it's always possible to find a black swan. If it's always possible to find a black swan then we can't make the inference to climb our tower upwards towards being and the mind of God -- and ultimately reality, all as a unity.

But if someone had something in mind other than Aristotle -- some modification which dealt with the notion that a single mind dealing with eternal categories does not bring one closer to being, but rather collective effort and distributing tasks and building trust such that we can work together, which tends to function better in an atmosphere where doubt is encouraged does.

Also, the reason I like using historical examples is because it's meant to get around the notion that stipulation of a difference between philosophy and science is uninteresting -- we can say it and put up our terms and use the terms thereon in that way, but that misses the point.

The historical examples provide a wider context other than standalone crisp definitions with syllogisms (though there's a time and place for that, too, I'm just explaining my method)
 

Are you able to say what each is? — Leontiskos

Not exactly, but by way of example I've hoped to show a difference -- Aristotle is the philosopher-scientist, Lavoisier is the scientist, and Kripke is the philosopher.

Not that I've been explicit or clear on this, really, but this is what the examples are meant to furnish -- as good examples of how to use the terms differently. The interpretation of each I'm meaning to use as why I might want to distinguish between the terms: look at what they mean and how they make inferences in these details and you'll hopefully catch onto the difference.

There won't be necessary and sufficient conditions -- I don't think we can solve the problem of the criterion, though I think falsification is still an important subject unto itself -- but there will be stark differences between two family resemblances when we compare them.

Trouble is, saying you know you have a pain is problematic. How do you justify such a claim? The only justification seem to be that you are in pain - the justification is the very thing being justified.

Thoughts? Are you happy to claim to know things that are unjustifiable?

Doleo ergo sum? I hurt, therefore I am!

What it excludes, is the trap of solipsism - resulting from doubting away the existence of the physical.

Pain, being prior to thought, cannot be doubted.

If we don't check every member of a set it's always possible to find a black swan. — Moliere

When you talk about "Aristotle's view of induction," what texts are you referring to? Or are you just thinking of Hume and conflating him with Aristotle?

Aristotle was not wrong in his time.

But neither he nor we can make induction a valid move that secures knowledge.

I say he wasn't wrong because I can see how his inferences are good given his circumstances, influences, and concerns not just from the rest of his writing but also from others' writings at the time, as well as writings about those writings.

But I don't think we can travel by induction up to knowledge of God, for instance. I'd say there is a limit of some kind on our ability to judge on some questions we might want to answer or try to answer, but don't seem like we can reliably answer. — Moliere

Well either he was not wrong or he was wrong. You seem to switch back and forth at least four times in these few sentences. Do you think Aristotle thought "induction" could secure knowledge? If so, and if it cannot, then you should hold that he was wrong.

I'm not sure that the process is sound. — Moliere

The process I outlined or some other one you are substituting? Here it is again:

Let's suppose that Aristotle thinks one should have wide experience before drawing a conclusion, and one should consult popular theories (or even all theories) to the best of their ability. Okay. I think that's right. Do you have some objection to it?

Because the idea that such a process is defeated... — Leontiskos

Because your argument looks to be invalid again. "There might be a black swan, therefore one should not have wide experience before drawing a conclusion, and one should not consult popular theories to the best of their ability." Non sequitur.

But if someone had something in mind other than Aristotle -- some modification which dealt with the notion that a single mind dealing with eternal categories does not bring one closer to being, but rather collective effort and distributing tasks and building trust such that we can work together, which tends to function better in an atmosphere where doubt is encouraged does. — Moliere

I am fairly certain that your familiarity with Aristotle is slim to none, but what you say here does not help your Humean notion of induction. Collective effort does not overcome the problems of Humean induction.

Are you able to say what each is? — Leontiskos

Not exactly, but by way of example I've hoped to show a difference -- Aristotle is the philosopher-scientist, Lavoisier is the scientist, and Kripke is the philosopher.

Not that I've been explicit or clear on this, really, but this is what the examples are meant to furnish -- as good examples of how to use the terms differently. The interpretation of each I'm meaning to use as why I might want to distinguish between the terms: look at what they mean and how they make inferences in these details and you'll hopefully catch onto the difference.

There won't be necessary and sufficient conditions -- I don't think we can solve the problem of the criterion, though I think falsification is still an important subject unto itself -- but there will be stark differences between two family resemblances when we compare them. — Moliere

This looks like another non-answer. If you want to say that science and philosophy are different, then you must be able to say what each is, and why the two are different. If you can't say what the two are and why they are different, then I have no idea why you would assert that the two are different.

Aristotle, Lavoisier, and Kripke? How many pages have you read of any of them? If they are to serve as exemplars of the putative categories you attach to them, then apparently both of us must have strong exposure to all three. That seems doubtful. I have read lots of Aristotle, a small bit of Kripke (less than 70 pages), and nothing from Lavoisier. Have you read enough of each to take them as exemplars of categories such as "philosopher-scientist"? If not, they are not going to function as exemplars of anything substantial. In that case they will just end up being empty vessels for post hoc rationalization.

This is why learning to make real arguments is important. "Philosophy and science are different, I can't say why, but I can point to Aristotle, Lavoisier, and Kripke as prime examples of the relevant differences, despite the fact that I have read very little Aristotle or Lavoisier." That's not a good argument, and what this means is that you have not provided any good reason for your conclusion. A good argument provides a good reason to believe the conclusion.

Pain, being prior to thought, cannot be doubted. — karl stone

Ok. Can it be known?

Have a look at Sam's answer. it's not just pain that cannot be doubted. Can you coherently doubt that you are reading this, and that it is a reply to your own post? Not if you are going to answer me.

You're not wrong, but there is more here...

Sam's answer - if we really doubted we'd keep banging into the furniture, has a certain normative value, and is not at all inconsistent with my approach.

But the question I'm addressing is 'How do we know what is real?' And, I'm not trying to make subjectivism work. I'm an objectivist - to deal in crude dichotomies. I'm also an evolutionary biologist locating knowledge of reality in the pain/pleasure instinct common to living organisms.

Pain signals potential harm or injury, prompting animals to avoid dangerous situations or seek protection. Pleasure reinforces behaviors that are beneficial for survival, such as eating, mating, and maintaining homeostasis.

When you talk about "Aristotle's view of induction," what texts are you referring to? — Leontiskos

I'm thinking about the physics, the metaphysics, on the weather, the prior analytics, the posterior analytics, parts of animals, and de anima.

The prior and post analytics serve as his epistemology -- how he goes about making inferences. One by deduction and the other by induction. His treatises on weather, the soul, and the parts of animals too serve as examples of Aristotle applying his epistemology to the world at hand. The physics serves as a precursor to the metaphysics in that it is both a particular and general science since it deals with the topic of change, itself an entry into the study of the most general categories.

I know you've read him and know him -- that's why I thought him a good example for us, and didn't think there'd be anything controversial in comparing his method to modern scientific methods and noting that they are different in what they are doing and arguing.

How many pages have you read of any of them? If they are to serve as exemplars of the putative categories you attach to them, then apparently both of us must have strong exposure to all three. That seems doubtful. I have read lots of Aristotle, a small bit of Kripke (less than 70 pages), and nothing from Lavoisier. Have you read enough of each to take them as exemplars of categories such as "philosopher-scientist"? If not, they are not going to function as exemplars of anything substantial. — Leontiskos

Yes. Aristotle I'd say I'm most familiar with, and the bit of Kripke we've been referencing in this conversation is something I've read here on the forums. Lavoisier's contribution to science is his meticulous work on making precise instrumentation, which I gather is a clear difference between what both Aristotle and Kripke are doing.

Now, readings get rusty and I make mistakes. But I'm not just using these just because -- Kripke got added to the mix, but Aristotle/Lavoisier is one I've just often thought through as a good comparison for finding a difference.

Also, what I've noticed is that between us is they are not good examples because it's only leading to accusations of ignorance and showmanship.

This is why learning to make real arguments is important. — Leontiskos

When you say this it seems like I must not know how to make a real argument, to your mind.

I'd rather say that arguments don't reveal truth as much as serve as a check to ourselves -- ah, yes, there I messed up, that inference can't be quite right.

Sure. We agree on much of this.

Are you comfortable saying you know things that cannot be justified? Saying you know you are in pain looks to be unjustifiable, so is it the sort of thing we can use as the epitome of "know"? Or is it more a fringe use?

I think it important to remember that Descartes' method of radical doubt in Meditations was not carried over into his conclusions. His subjectivism is rescued from solipsism by faith, that 'God cannot be a deceiver' - and so radical doubt was jettisoned, and the world - experienced subjectively, is restored to him.
As a Galilean, I find it deeply unsatisfactory.
I think knowledge obtained via the senses can be justified as providing an accurate picture of reality because we evolved, and could not have survived were we misled by our senses.
Pain is prior to intellect both in terms of phylogeny and ontogeny - (roughly, the evolved organism and the developmental individual.)
Furthermore, the universe is entropic - everywhere good is uphill! We must spend effort and energy just to stand still; more if we wish to progress. It hurts! And that's how we know it's real.

Ok.

I'm not overly thrilled with Descartes. Been a while, other ideas came along. So arguing against him is superfluous. Unnecessary.

Knowing that you have a pain in your foot is not exactly like knowing there is a screen in front of you becasue you can see it.

Seem to be a few things being treated as one here.

The sceptic's argument is irrefutable, but pointless.) — Ludwig V

Has this been proven to you, "The sceptic's argument is irrefutable".? If so, please let me know what this demonstration looks like.

But I don't quite see why you say both that you don't agree that the sceptic's argument is irrefutable and that it is impossible to prove or disprove. — Ludwig V

Let's see if I can make this a little clearer. I am not saying, I can prove or disprove the radical sceptic's argument. What I am saying is one can't talk about proving or disproving the radical skeptic's argument. Why? Radical Skepticism acts like a work of fiction. A work of fiction does not make assertions to prove or disprove, the very nature of a work of fiction is an absence of any assertion about the world. There is nothing to confirm or falsify in a work of fiction. So, like a work of fiction, there is nothing to confirm or falsify in the skeptic's argument as well.

I agree, Descartes is superfluous, and somewhat blameworthy for developing subjectivism to protect himself from the ire of the Church visited on his contemporary, Galileo.

You see screen in front of you - you know it is real because you can see it, and you trust the evidence of your senses because you're are an evolved organism; that has survived evolution in relation to painful realities you wouldn't survive if your senses were not accurate to reality. You can be more sure of the conclusions you draw from the evidence of your senses if your observations are confirmed by an independent party, and that's empirical method.

Makes sense to me, painful feet notwithstanding!

Good analytic arguments.

You'll get a pushback against "you know it is real because you can see it" from the idealists and solipsists, who will claim that it might be an hallucination or other phantasm.

My response is that I don't much know what it means to say that it's a real screen until you tell me what the alternative is - a cardboard screen or a result of the acid drops or whatever. But I'll point out that you and I can agree that it's a screen and get on with the conversation on that basis. That is, we can agree not to subject the screen to doubt. Hence the independent party bit.

The point that we find ourselves embedded in the world is a good one - even if you put it in terms of being an "evolved creature".


So, unfortunately, I'm not seeing a substantive point of disagreement between us. Except the foot pain... I can't feel the pain in your foot.

So we might say that using a name involves a rigid designation — Banno

I wonder how we make sense of such claims as "if I were you then ...." (or to use proper nouns, "if Michael were Banno then...")

Strictly speaking if "I" and "you" are being used here as rigid designators then the antecedent of this conditional is a contradiction and so necessarily false and so the conditional always true. If I were you then I’d be a billionaire!

But this analytic interpretation of the phrase seems misplaced. It's not how we ordinarily understand it. Perhaps we're not using rigid designators, or perhaps rigid designators are not always that rigid.

You'll get a pushback against "you know it is real because you can see it" from the idealists and solipsists, who will claim that it might be an hallucination or other phantasm. — Banno

Sure, but 'seeing' is the ideal minimum sensory experience, employed for the sake of philosophical simplicity. If still in doubt, touch it, lick it, throw something at it - the screen can be shown to be real by the evidence of the senses.

Subjectivists drive me nuts, because it's not the screen they don't believe is real, but the very concept of 'real' they're throwing into question for no adequately justified reason; in a way that Sam disputes in his post with regard to the normative value of experience.

We don’t know reality in the same way we know facts; instead, we act with a certain conviction that things are real. This acting isn’t based on reasoning or evidence; it’s the foundation upon which reasoning and evidence even make sense. — Sam26

Absolutely. This is why Descartes adoption of a method of radical doubt, to establish subjective certainty is so methodologically incoherent, why it results in solipsism, and requires rescuing from the corner into which he paints himself by resort to faith. 'God cannot be a deceiver."

Descartes was just saving his skin. Galileo was right; and scientific objectivism should have informed the past 400 years of Western philosophy. Be a very different world.

Sure, but 'seeing' is the ideal minimum sensory experience, employed for the sake of philosophical simplicity. If still in doubt, touch it, lick it, throw something at it - the screen can be shown to be real by the evidence of the senses. — karl stone

Clearly that’s insufficient as those suffering from
psychosis can see and hear and feel things that aren’t really there.

How do I know that I am not a schizophrenic hallucinating a world?

We (believe we) have rational grounds to trust our sensations.

Clearly that’s insufficient as those suffering from
psychosis can see and hear and feel things that aren’t really there. — Michael

It's weirder than that. Stroke victims can have serious perceptual disorders; if rendered unable to process sensory information properly it results in the most extraordinary subjective hallucinations. However, this is related to physiological abnormalities in the brain. These are discussed in the book: The Man Who Mistook His Wife for a Hat and Other Clinical Tales - by neurologist Oliver Sacks.

How do we know we're not hallucinating reality? We are, to some degree. The internal representation of reality is not reality itself - and that's why things can get weird when the brain is damaged. Yet all this is missing the point that human beings survived, and evolved in relation to a physical reality - of which, we must be able to establish valid knowledge, or would have become extinct.

Yet all this is missing the point that human beings survived, and evolved in relation to a physical reality - of which, we must be able to establish valid knowledge, or would have become extinct. — karl stone

Well this just begs the question. The skeptic questions the existence of the world-as-we-understand-it. Perhaps idealism is correct. Perhaps we’re artificial brains in a vat. Perhaps we’re being deceived by an evil demon.

So to put simply; perhaps we didn’t evolve via natural selection in a physical world in which “accurately” sensing our environment is a requirement for survival.

Of course I’m not suggesting that such doubt is warranted, only that your reasoning against it presupposes its own conclusion.

Yet all this is missing the point that human beings survived, and evolved in relation to a physical reality - of which, we must be able to establish valid knowledge, or would have become extinct. — karl stone

Cockroaches have survived a lot longer than h. sapiens. Does that mean they have valid knowledge?

Depends really, I suppose - what you term knowledge. But I generally consider humans distinct from all other animals - as possessing a qualitatively distinct form of apperception that results in knowledge as I would define it.
Sure, a cockroach will flee when a light comes on suddenly; so clearly it has a degree of apperception, but is this knowledge? I don't think so.

Okay, but again, it's messy. If the question is 'what's real'? what is the radical skeptic's real reason for dismissing the evidence of the senses?

My answer to the radical skeptic is pain, because it implies an objective reality in terms prior to cogito, that cannot be doubted. i.e. Descartes should have put his hand in the fire - and he couldn't possibly doubt away all that could be doubted while his fingers melt, instead of a ball of wax.

And one can consider sensory perception as derived by evolution from the pain/pleasure instinct.

My answer to the radical skeptic is pain, because it implies an objective reality in terms prior to cogito — karl stone

Why? Perhaps pains are an hallucination. Or, rather, perhaps they are not caused by a real fire in an external physical world but by a mad scientist prodding my envatted brain or by an evil demon?

Sort of. We might say Homer is the guy we think wrote the Odyssey. But turns out it was Kostas who wrote it. Now at stake is the difference between thinking of "Homer" as denoting exactly and only "the bloke who the Odyssey", and thinking of it as denoting Homer, that person. That's what this group of thought experiments target. And that in turn is the difference between the descriptive theory of reference and the idea of a rigid designator. If "Homer" and "Kostas" are rigid designators, then we can say that it was Kostas that wrote the Odyssey, and do so without fear of our system of reference collapsing. If we think in terms of the descriptive theory, and so "Homer" refers to "The guy who wrote the Odyssey", then "Homer" refers to Kostas. — Banno

I see that. But then, it seems to me to be a matter of how one thinks about it, or perhaps what question one asks. "Homer" designates just that person every time it is used. Whether we know or how we can establish just which person that is, is not a relevant question. What bothers me is that it reminds me of the power of "+1" to define an infinite numbers of steps in advance - an astonishing fact. But, of course, it isn't astonishing at all. We apply the rule and discover or generate (I don't care which) the answer. It seems to be specified in advance because we are so sure how the rule will be applied in every case. In the same way, it seems to me, "Homer" identifies the same person in every possible world (in which Homer exists) not because it can somehow reach out across all possible worlds, but because we will decide, in all possible worlds, which person is Homer - and we will decide on the basis of the facts of the case. There's no list of facts that will determine every outcome in advance, but some facts or other will determine it.
So, are"Pegasus" or "dragon" rigid designators?

There's the point, too, that we might well see that the descriptivist theory is inadequate and yet not have at hand another theory to replace it. We sometimes have to be comfortable to say "I don't know", and to see that doing so is better than trying to repair a defunct theory. — Banno

Oh, I agree with that. I count myself among the don't knows. On the other hand, I'm not committed to a binary option for theories, though intention doesn't have anything to recommend it that I can see.

It's not a property because that "a" designates a is not a formula within the system, but part of the interpretation, of the model. — Banno

OK. Interpretation sits outside both syntax and semantics, but links the two. Since it isn't a formal system, it looks to me as if it may be conducted in natural language?

Much of the apparent bumpiness here might be worked out by your looking at the formal system and how it functions. You seem to have. good intuitive grasp of the ideas involved. — Banno

H'm. I'm an old dog. But if all this is something that logicians need, I have no problem - any more than I do about what mathematicians get up to. It's when ideas get out into the rough country beyond logic (or mathematics) that I sit up and take notice.

David Chalmers, who agrees more or less with the Wittgensteinian argument that we usually don't use "real" in this way, but goes on to ask why we couldn't. He proposes a room in to which we can go, within which we can ask such questions, and discuss the consequences. — Banno

That's a very interesting idea. It has occurred to me that some philosophers present their anti-realist arguments together with some account of what reality actually is. Which might get round Austin's objection. I'm thinking of Plato, Berkeley, Dennett and perhaps Descartes. You wouldn't know where I could find some discussion of this, would you?

I think knowledge obtained via the senses can be justified as providing an accurate picture of reality because we evolved, and could not have survived were we misled by our senses. — karl stone

On the face of it, there is something wrong here. We are frequently misled by our senses, and yet we have survived - or at least enough of us have survived.

Radical Skepticism acts like a work of fiction. A work of fiction does not make assertions to prove or disprove, the very nature of a work of fiction is an absence of any assertion about the world. There is nothing to confirm or falsify in a work of fiction. So, like a work of fiction, there is nothing to confirm or falsify in the skeptic's argument as well. — Richard B

But doesn't a work of fiction have to present something that is possibly true? The anti-sceptical arguments that I've seen aim to prove that the sceptic's conclusions are not even possibly true.

Absolutely. This is why Descartes adoption of a method of radical doubt, to establish subjective certainty is so methodologically incoherent, — karl stone

I'm definitely not a fan of Descartes, so I agree.

Descartes begins by doubting everything, until he arrives at the cogito ("I think, therefore I am") as something indubitable. However, Wittgenstein would challenge the very possibility of such a universal doubt.

In OC, Wittgenstein would argue that doubt is not an autonomous or foundational act but rather depends on an unquestioned background. For example, he points out, "Doubt itself rests only on what is beyond doubt (OC 115)"

For Descartes to doubt everything, he must already be operating within a framework of language, thought, and experience. Doubt is a language game that requires a stable context, it's not a solitary exercise.

Wittgenstein demonstrates that certain beliefs (e.g., "The Earth has existed for a long time," "I have a body") are not the result of inference but are intrinsic to the form of life that makes reasoning possible. To doubt these very basic beliefs would be to undermine the very conditions for meaningful doubt.

Descartes is using doubt as a methodological tool to arrive at objective certainty, but this is a misunderstanding of how doubt functions in everyday life. "Doubt is not a state of mind, but a way of acting (OC 370)."

Descartes’ radical skepticism is not a genuine doubt but a philosophical fiction. The attempt to justify everything leads to an infinite regress or to nonsense.

I want to be clear - Wittgenstein uses certainty in OC in two distinct ways. Subjective certainty (like a conviction), and objective certainty, which can be used as a synonym for knowledge. These are different language games, and both are important.

You'll get a pushback against "you know it is real because you can see it" from the idealists and solipsists, who will claim that it might be an hallucination or other phantasm. — Banno

I'm an idealist, but I would argue very differently from most idealists. I try to keep these language games separate unless there is a reason to bring in metaphysics.

Why? Perhaps pains are an hallucination. Or, rather, perhaps they are not caused by a real fire in an external physical world but by a mad scientist prodding my envatted brain or by an evil demon? — Michael

So are you saying this evil demon brain jar keeper can induce you to put your hand in the fire? If so, can he induce you keep it there? Or is it by your own will that you would put your hand in the fire to test reality? Is it by your own will you engage in radical skepticism such that the very concept of reality is undermined? Or do you have no choice but to do so because the evil brain jar demon is prodding the synapses?

Sure, a cockroach will flee when a light comes on suddenly; so clearly it has a degree of apperception, but is this knowledge? I don't think so. — karl stone

Which was my point. Adaptive ability is not an argument for the veracity of judgement.

So are you saying this evil demon brain jar keeper can induce you to put your hand in the fire? If so, can he induce you keep it there? Or is it by your own will that you would put your hand in the fire to test reality? — karl stone

I’m saying that there is no fire and no hand. We are brains in a vat and a mad scientist is using diodes to stimulate the appropriate areas of our brain to cause us to see/hallucinate a fire, see/hallucinate our hand in the fire, and feel/hallucinate our hand burning. And when he detects that we intend to remove our hand from the fire he stimulates the appropriate areas of our brain to cause us to see/hallucinate our hand being removed from the fire and stops stimulating the areas of the brain that cause us to feel/hallucinate our hand burning.

Is it by your own will you engage in radical skepticism such that the very concept of reality is undermined? Or do you have no choice but to do so because the evil brain jar demon is prodding the synapses? — karl stone

Could be either. Perhaps the mad scientist is also stimulating the areas of the brain responsible for decision-making. Or perhaps he finds it more entertaining to leave those areas alone.

Adaptive ability is not an argument for the veracity of judgement. — Wayfarer

No, it's an argument for the basic veracity of sensory perception, to reality. Apperception is something else again, and knowledge is more than mere apperception. Now you're adding the concept of judgement. I can't keep up!

I’m saying that there is no fire and no hand. We are brains in a vat and a mad scientist is using diodes to stimulate the appropriate areas of our brain to cause us to see/hallucinate a fire, see/hallucinate our hand in the fire, and feel/hallucinate a burning hand. And when he detects that we intend to remove our hand from the fire he stimulates the appropriate areas of our brain to cause us to see/hallucinate our hand being removed from the fire and causes the painful sensation of a burning hand to lessen/stop. — Michael

Wow, it must suck being an evil brain jar demon! Question is, what evidence is there for the existence of such a being? None at all. And it's perverse to multiply entities beyond necessity, according to ye olde Bill of Occam. The method of sceptical doubt taken to such extremes that it undermines the very concept; reality - supposedly being investigated, is the rankest sophistry.

If you insist on engaging in such arguments, at least accept their true logical implications, which is solipsism; and inability to know anything beyond the mere fact of your own existence. I think therefore I am, and that's your lot.