68

The issue here, as it often is, is that colloquial English is horribly ambiguous, which makes any sort of precise and rigorous discussion difficult. But with sufficient effort, it is possible to make claims precisely, and once you do that, the problem disappears. Alice states that the sky is blue. Bob states that we live in a simulation. Let's assume for ...


64

I think the distinction is that people often conflate "negative obervations" with "absence of evidence". To take the Santa example - if you simply declared "I have no evidence that Santa exists, therefore he does not exist", then you would be arguing from an absence of evidence. However, if you said "Santa is said to travel in a flying sleigh, and no radar ...


29

Elliot Sober offers a useful argument on this : "Absence of evidence isn't evidence of absence" is a slogan that is popular among scientists and nonscientists alike. ... There has been some philosophical work on the motto that doesn't use a probability framework and it provides a good way of isolating the problem I want to address. Here are ...


19

Welcome to the demarcation problem of science. What is this thing called science? In lower levels of education, one is often given the impression that 'science', whatever that may be, exists as a monolithic entity. There is no sufficiency and necessity definition of what science is. It's better to say 'sciences' or 'scientific' when speculating as to this ...


10

Circular argument We know it's a trilemma because the argument is founded on logic and proofs, and all proofs will end in either circular logic, infinite regression, or a foundational assumption. Infinite regress You can always break a proof into parts. Those parts get simpler and simpler. Keep breaking them up long enough, and all parts will eventually ...


8

Logical omniscience was always only a technical problem related to formalization of epistemic logic in terms of possible worlds. Since classical possible worlds are supposed to be consistent and deductively closed they must include all the consequences along with their premises, and nothing contradicting the premises. So if we are describing acquisition of ...


8

Go into your kitchen. Is there an elephant? In this case, absence of evidence is evidence of absence. You know that if there was an elephant, you would have evidence. No evidence, no elephant. But is there a mouse? It is quite possible that there is a mouse but no evidence. So you need to decide two things: How likely is it a priori that a statement is ...


8

This question arises in the context of the traditional philosophical enquiry into the nature of knowledge. We might summarise that enquiry as: under what conditions is it correct to say that a person X knows that a proposition P is true? To emphasise the point: the analysis is not concerned with the conditions under which P is true or accurate, but the ...


8

Yes, an argument with false premises and a true conclusion can be valid. For example: All cats are human Socrates is a cat Therefore, Socrates is human The argument has false premises and a true conclusion. But the argument is valid since it's impossible for the premises to be true and the conclusion false. In other words, if the premises are ...


8

What is Science? The Popperian view of science is that a claim is "scientific" if it can be falsified. Science cannot prove that a hypothesis is true, only that it is manifestly false. If economics can make falsifiable claims, then I think it is justified to say such claims are "scientific", at least on some level (the degree of repeatability is certainly ...


7

The problem is not unique to knowledge. The problem is sometimes called "Frege's Puzzle", and it applies to a variety of mental states. For instance: Lois believes that Superman is strong. Lois doesn't believe that Clark Kent is strong. Lois wants to meet Superman. Lois doesn't want to meet Clark Kent. Lois is curious who Superman is. Lois isn't ...


6

In standard philosophical parlance 'epistemology' and 'the theory of knowledge' are convertible, interchangeable. A crack of light might, however, develop between them. 'Epistemology' as practised in philosophy is concerned with questions such as 'how is knowledge of the external world possible ?', 'can we know other minds ?', 'is a priori knowledge possible?...


6

If we're talking about metaphysical possibility, then normally yes. If you reject the claim that "if P then possibly P", you must also reject the claim that "if necessarily P then P". Proof: suppose we reject truth implies possibility (that is, we reject that for every formula P, if P then possibly P). Then for some formula A, we have A and not-possibly A. ...


6

I will make several suggestions, although I am not certain that I interpret the question as intended. The strongest case (arguably) for philosophical foundations to epistemology in modern times, including the idea that positive sciences require such an inquiry into their foundations to function properly, was emphatically made by Husserl throughout his life. ...


6

Bertrand Russell, Problems of Philosophy (NY: H.Holt & Co., 1912), p.131 If a man believes that the late Prime Minister’s name begins with the letter B, he believes what is true, since the late Prime Minister was Sir Henry Campbell Bannerman. But if he believes [we can add: for good reason] that Mr. Balfour was the late Prime Minister, he will ...


6

You have misunderstood the point of the Munchausen Trilemma. It plays a key role in the process of philosophy showing that none of our beliefs are justified knowledge, per the standards of "reasoning". Most people hold that they have knowledge and beliefs based on justified reasons, and that beliefs SHOULD be justified, and knowledge isn't knowledge unless ...


6

There are plenty of issues with subjective probability assignments to degrees of belief discussed e.g. in SEP's Subjective Probability Theory. I will only address the one outlined in the OP. For a book length treatment see Fundamental Uncertainty: Rationality and Plausible Reasoning volume edited by Marzetti and Brandolini. The idea of distinguishing ...


6

Consider what the second person said: You cannot prove that we are not in a simulation and that anything is real, hence you cannot prove that your claim was true. This may be an example of an argument from ignorance. Here is how Wikipedia describes it: Argument from ignorance (from Latin: argumentum ad ignorantiam), also known as appeal to ignorance (...


6

Pointing out that induction is necessary for claims about the world doesn't actually resolve the problem of induction. At best, it shifts the problem from purely formal matter of reasoning to a more embodied matter of cognition. The problem of induction is a problem of forecasting. We have a stream of experiences that we have lived through encoded in memory....


5

I don't quite see how one could have a priori knowledge of any truths about taxes. There is no consensual definition of a priori knowledge but suppose we try tthe following two approaches : (SC) S's belief that p is justified a priori iff S's belief that p is justified by a nonexperiential process and that justification cannot be defeated by ...


5

I suppose it's convenient to be able to label things you want to be true but can't come up with good arguments for as "a priori truths", but you do have to get other people to agree with you. An a priori truth is one that's true regardless of experience, so clearly it has to be true in all possible situations. Not all societies have had legal systems, so ...


5

Obviously truth implies possibility. So let me make a case for truth not implying possibility. Let's start with an "applied logic" example. Suppose I'm trying to reason about the world using imperfect information (i.e. my senses and informal induction). At any given moment, I'll have some idea of what the world is, but that idea will probably be ...


5

The fact that we make inferences from sense experience is not the problem of induction as presented by David Hume. The problem of induction is to find a reason for those readily made inferences. Leah Henderson describes the problem of induction as follows: Hume asks on what grounds we come to our beliefs about the unobserved on the basis of inductive ...


4

A better phrase is "absence of proof is not proof of absence". One definition of "evidence" is that E is evidence for H if seeing E justifies a Bayesian update that increases the probability assigned to H. And if all the relevant probabilities are in the open interval (0,1), then E being evidence for H under this definition means that (not E) is evidence for ...


4

Welcome to PSE, 0x90. Analysing the innate We need to distinguish between innate ideas and innate belief and knowledge. The two are often conflated but one might have innate ideas such as the concept of God (as many though not myself have claimed) without having an innate belief, let alone innate knowledge, that God exists. Innate ideas - Socrates and ...


4

The situation you describe would not be a counter-example to Occam's razor but just a reminder that it's a rule of thumb. It does not say that the simplest theory is always correct, it says that given two equally effective solutions the one that requires the least hypotheses or hypothetical entities is to be preferred. It is very common for a theory to ...


4

Problem of objective definition of beauty For something to be a property, it must be objective, i.e. it must be independent from observer. From purely skeptical position, we could declare anything perceived empirically to be subjective. Yet, although strictly speaking true, this is not very practical - it reduces philosophy to infertile solipsism. ...


4

The trilemma is about justification of a given proposition. Any justification, so the story goes, takes ultimately one of these forms if faced with skepticism. Therefore, the third option is about people who answer to the question "But how do you know that x really is true" dogmatically, e.g. with "Because it is", "Because I say so", etc. Ultimately, the ...


4

There's several interlocking questions you're raising. First, there are three major theories of why we punish crime as a society. You've identified two: Reform - that the punishment is about rehabilitating the criminal (a view largely associated with Mill) Deterrence - that by having punishments we decrease crime Retribution - that crime requires ...


4

"Valid" in logic is just a technical term meaning that if the premises are true, the conclusion logically must be true as well. As you pointed out in another question, a special case of this is when the conclusion is a tautological sentence, in which case it doesn't matter what the premises are. For non-tautological conclusions, though, validity is ...


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