There are tons of resources available, from short and entertaining to rigorous and comprehensive. The Internet, the book and multimedia market, the educational institutions are saturated with excellent information about evolution. Finding information is easy - but you have to want to find it in the first place. Your mind has to be open and ready for change.

But when you meet a skeptic and start shoving your facts and arguments in their face, all you ever do is entrench them even further in their skepticism. Even someone who started out pretty indifferent to the issue will come away with a much stronger opinion - and not in your favor.

This phenomenon is by now well-known in psychology, but I didn't even need psychologists to tell me about it, because believe me, I've observed it first-hand more times than I care to recount.

You must be pretty new to the Internet, or more generally, to interactions with people, if you think that you can "explain evolution to a skeptic." No "skeptic" of evolution (climate science, physics, medicine, etc.) has ever changed their opinion as a result of being confronted with relevant facts and arguments.

He's been banned several times on this forum and the old one. IIRC his previous incarnation here was "tom". I thought then that he'd reached the limits of his imagination in coming up with new sock-puppet names.

That's a dodecalemma ;)

Anyway, what use is my knowledge to me if I have died?

A "physical property" is, first of all, a theoretical concept. Different theories posit or imply different physical properties. So in one sense, one can quite easily imagine a physical property that did not exist before: just assume a historical stance and consider, for instance, that temperature was not a "thing" before it was made part of 19th century thermodynamics, and even then different theories defined and operationalized in different, sometimes contradictory ways. Other theories do not even include temperature in their ontology of properties. Future theories, such as theories of quantum gravity or perhaps new theories in climate or materials sciences, may introduce heretofore unknown physical properties.

Flip this property/theory relationship, and you can readily imagine physical properties that do not exist even in principle. One end of a scientific theory is an abstract construct - the other end is supposed to be anchored in reality. Lift that anchor and use your imagination freely to construct a theory that does not seek to model anything in reality. Chances are, this theory will have nonexistent physical properties built into it.

This morning I decided to drink a cup of tea with my breakfast, it was departing from my habit of drinking coffee. It seems to me that I arrived at this momentous decision freely being under no duress whatsoever to do so, I even had a rationale for that decision having read somewhere about the health benefits of drinking tea. However, that is not the way a determinist would look at my decision — Jacob-B

Why?

I am not asserting determinism, but just want to point out that nothing that you said is in any tension with determinism.

You say that the concept of motion is available to eternalists, but it seems logically incoherent to me. You claim that motion or change can(?) happen in the past or in the future, but it fails to explain when anything actually happens in the block universe. — Luke

I don't understand your question. Again, motion is change (specifically, of position, or more generally, of any property) over time. How is this a problem for eternalism? There are timelines, and there are properties that change along those timelines. What, specifically, is incoherent in this picture?

Future events already exist, so have they already happened? — Luke

You are just needlessly confusing yourself with this existence business. Like I said, I don't see much use for it, but if you insist on talking about it, just think logically. Every event in a block universe has a spacial and a temporal coordinate: (x, t). So if you ask when an event exists, the only sensible answer is the obvious one: it exists at t. Just as if you ask where it exists, the answer would be x.

You seem to be saying that motion is separate from temporal passage, but isn't the present moment when motion occurs and events happen? — Luke

We directly perceive motion with our senses in our subjective present (obviously), but we conceptualize motion as change over time, which can happen in the past or in the future, here or there, perceived or unnoticed. This concept of motion is available to both presentists and eternalists, but presentists will additionally qualify it with an objective temporal modality.

If I threw a ball in the air yesterday, and that event eternally exists according to eternalism, then is that ball still in motion (now) according to eternalism? — Luke

Yeah, this is where I definitely part company with both parties. Not that I think that either of them is wrong - I just think that this talk of existence is both confusing and pointless. I'll leave it to advocates to untangle this mess.

I still don't understand. If presentism posits a passage of time while eternalism does not, then how is motion possible according to eternalism? — Luke

When presentists posit a passage of time, what they mean (or at least what some of them mean) is that the present time is an objective fact. Time flows by way of the present time constantly progressing forward - and that too is an objective fact of the world. This present time, which is like a moving index on every timeline, is not implied or required by any physical law. As far as physics is concerned, positing such an index is unjustified. And that is what moves (at least some) eternalists to deny the objective existence of such an index.

Why is it referred to as a static block universe? — Luke

I think that the use of the epithet static in relation to the block universe is pointless and misleading. At best, it indicates that the block as a whole does not change - which is just a way of saying that there isn't a second time dimension, along which the block could be changing. But since no additional time dimensions were ever on the table in the presentist/eternalist debate, it is unclear why this needs to be brought up at all.

The existence of the one and only time dimension is acknowledged by both presentists and eternalists - with all that that implies: where there is time, there is motion.

We all have our metaphysical preferences when it comes to time (eternalism, presentism, possibilism). What we should not be doing is claiming that our preferences have been verified by the only possible interpretation of physics (either general relativity or quantum mechanics). — prothero

Presentism is commonly thought to be incompatible with the relativity of simultaneity - a fundamental implication of Special Relativity. It does not depend on any particular solution or interpretation; it is not in conflict with quantum mechanics (quantum mechanics has been formulated in SR); and it is very well established experimentally.

However, whether presentism is indeed ruled out by relativity depends on exactly what claims are made in the name of presentism. Lots of arguments have been put forward for and against compatibility - go and look for them, if you are interested. (But who am I kidding...)

Why does the article say that the flow of time, or passage through space-time, "must presumably be a mental construct or other illusion"? — Luke

Because it is talking about "the flow of time, or passage through space-time," rather than motion. There is no difference in dynamics between eternalism and presentism. In fact, there is no physical difference, period. The difference is entirely metaphysical and has to do with metaphysical notions, such as the objective present, the passage of time, the existence of past and future, etc.

It may help to know that it was shown in the early 20th century that any set theory that allows there to be a 'set of all sets' is inconsistent. So if your 'domains' are like sets, your theorem will probably be doomed to the same fate (that's one reason why it's crucial to define "domain"). — andrewk

Yes, this is why the ZFC set theory - which since its introduction as a replacement for the naive set theory in the early 20th century has become a standard axiomatization of sets - includes the Axiom of Regularity, which implies that no set is an element of itself.

Well, they 'rewind' along with the rest of 'history', which isn't even a violation of physics. Only what you (the 'traveler') are doing is a violation. — noAxioms

What do you mean "they rewind"? The idea of time travel is that someone (or something) is moving in time (at a different than normal rate), while everyone and everything else goes on as if nothing happened. But how this divergence is possible if there is only one now is something I can't wrap my head around. It would make sense if now diverged as well.

What I've said is that, according to my view of presentism, no other times but the present time exist, and time travel can only be viewed from an eternalist or B theory perspective of time. — Luke

No times but the present exist, and wherever the present is, that is what exists. Yesterday the present was thataway, and now the present is thisaway. Nothing about presentism says that the present has to stay in one place.

I know about industry sponsorships and grants, but those are mostly relevant to graduate and faculty research projects. The college gets a cut, but most of the money goes towards paying grad students/post-docs and for research expenses like equipment and travel. Bottom line is that much of research in engineering, CS, some social and human science and some fundamental science pays for itself; not so much in pure math and humanities, I guess. But undergraduate programs are payed by tuitions, endowments, investments, etc. (That joke must have been made up by an undergrad.)

Don't forget that some of the greatest theories in the world were created using wax tablets and sticks to draw in the sand and just plain old conversation with other thoughtful persons. — NKBJ

Well, it depends on what you are planning to do. You know that old joke about scientists, mathematicians and philosophers? From the point of view of the administration, mathematicians are better than scientists (or engineers), because they don't need all that expensive equipment and materials, field trips, etc. All they need is paper, pencils, and a waste bucket. And philosophers are even better: they don't even need the waste bucket.

I think it's important to remember that the motivation, the main selling point of presentism is this inescapable subjective perception of being in time - and that includes both the instantaneous now and its temporal progress. However we choose to formalize and articulate presentism, we shouldn't lose track of those basic intuitions, else this turns into a sterile formal exercise.

I presume you ride the 'now' into the future. That's how it worked. To travel to the past, I suppose you'd have to get time to go the other way, and still be able to ride it, but leaving everybody else behind. — noAxioms

This works for the Traveler, but what about the rest of us? What happens to us and our now when the Traveler departs into the future or the past, and now departs with him?

In more objective terms, I think time travel to the past would be to cause an instance of 'yourself' to exist at time X, but with memory of time Y, with Y > X. This is pretty easy to do in theory in the forward direction, but not so much backwards, being a violation of the principle of locality. — noAxioms

We can imagine a world in which, in the year 2019, you stepped into the time machine and suddenly disappeared. Earlier, in the year 1919, an exact copy of you as of 2019 suddenly appeared in a field, fooled around for, say, a week, and then disappeared. Meanwhile, in the year 2019, five minutes after vanishing in the time machine, you reappear, having the memories and other physical changes that your copy had in 1919 at the time of disappearance.

We could tell the same story chronologically, without jumping back and forth between 2019 and 1919. The reason we usually tell these stories achronologically is to emphasize causal connections. But in this telling there are no anomalous causal connections between the past and the future - and that is why it does not count as time travel. Time travel is all about anomalous causality.

I always wondered what meaning there is being a unit of X per X, which seems to reduce to just unitless '1'. On the other hand, our clocks are dilated mostly due to the gravity well in which we find ourselves, so maybe the rate is still unitless, but still less than 1. How much less is an eye-opening exercise. — noAxioms

Yeah, I only invoked that formula in order to represent the difference between normal time flow and time travel as a difference in the rate of time flow (as seen from the presentist standpoint). Note that in non-inertial reference frames your local time still passes at the usual rate.

Depends on whether you are talking about undergraduate or graduate education. A question about the "quality of education" in general would make more sense for undergraduate education. For graduate education you would be more interested in specific departments that have a high standing in their field, and even specific professors with whom you would like to study.

As for undergraduate education, you'll hear a lot of platitudes, but don't underestimate such down-to-earth factors as the wealth of the institution. A well-off college will have more and better teachers, more teaching assistants, more and better facilities, including science labs. All this factors into the quality of education.

You need presentism of course. Travel isn't possible at all in eternalism, given the usual A-definition of 'travel'. — noAxioms

What do you mean?


Thinking a bit more about this, if now is an objective fact on presentism, and the Time Traveler is transported some ways into the past or the future, what happens with the now? The situation is different from the normal "time travel" when everyone moves forward into the future in lockstep at 1 second per second, because the Traveler has left everyone else in the future (or the past). The only way this makes sense to me in the presentist framework is if now splits into two nows: one travels with the Traveler (where it entangles everyone else in his present) and one stays with his former contemporaries and continues on at its usual pace.

Note that these considerations are quite apart from the question of existence of the past and the future (which, frankly, make little sense to me).

According to you, time doesn't pass at all, according to presentism. That can't be right. And I don't mean that in the sense that presentism can't be right, but in the sense that your construal of presentism can't be right.

The A theory holds that only the present time (and everything at that time) exists. Therefore any time other than the present time is not an available travel destination. This appears to rule out the possibility of time travel according to the A theory

However, there is one caveat, which is that the present time is always moving into the future.. — Luke

Exactly. So, presentism doesn't exclude all time travel. I don't see why presentism as such should be inimical to other kinds of time travel, proceeding at different rates than the normal forward rate.

Consider the following circular definition, which nevertheless has intuitive meaning. — sime

Determinism is the thesis that the state of the universe at any given time, together with the laws of nature, fixes (determines) the states of the universe at all other times. — SophistiCat

It's not circular, just because the word 'determines' occurs in the definition. You can easily rewrite the definition without that word.

But this definition is also fulfilled by taking determinism to refer only to the fixing of an arbitrary finite number of states. — sime

No, some is not the same as all, so your definition does not fit the above. I've never seen determinism used in this sense, so I don't see why this should be taken seriously.

It may fix an event with 50% probability from the perspective of a conscious observer, but still be determined by the universe itself. — Karl

No, I specifically said that it is fixed by "the state of the universe, together with the laws of nature" and contrasted that with what you are saying. The former would contradict determinism, the latter would not.

Say there is a 50/50 chance of some event occurring. How does that probability factor affect whether or not the universe is deterministic? — Josh Alfred

Determinism is the thesis that the state of the universe at any given time, together with the laws of nature, fixes (determines) the states of the universe at all other times.

Where does the 50/50 probability come from? If you are saying that the state of the universe, together with the laws of nature, fix some event with only 50% probability, then that directly contradicts the deterministic thesis. If you are saying anything other than that, e.g. that it is your subjective assessment of some outcome based on limited information, then it is irrelevant to determinism.

The switch being on and off is an example of an inconsistent state of affairs. The SEP entry for States of Affairs gives the example of Paul's having squared the circle.

Also paraconsistent logicians accept or at least consider the existence of inconsistent physical objects. — Andrew M

See, we can say what it means for a sentence (for example) to be inconsistent. I don't think it is possible to say what it means for an object or a state of affairs to be inconsistent - without looping back to the language that we use to describe that object/state of affairs. So yes, you can sort of attribute inconsistency to things, but that attribution will be parasitic upon language, thought, reason. Of course, things and talk of things are hard to separate anyway, except that if we are realist to any extent, we accept that there is a one-to-many relationship between them. That is, there is one thing, but our relationship to it is through thinking/talking about it, and there can be more than one way to do the latter - including dialetheic ways.

Take the superposition state in quantum mechanics, for example. One way to talk about it is through the use of the quantum mechanical formalism, and there is nothing inconsistent about that - it's just straightforward linear algebra. But sometimes people feel that the mathematical formalism doesn't give us the feel, the intuitive understanding of what the thing is, and they try to accommodate it in more familiar, human-scale classical terms. Or they are actually committed to the view that, at least for macroscopic things like cats, such terms should always apply, quantum formalism be damned. One way or another, they can end up talking about the superposition state using a deliberately inconsistent model. Does it make the subject of their description itself inconsistent? Yes, as long as they are talking about it in that particular way, and with the understanding that the inconsistency awes itself to that particular conceptualization.

What separates logic from opinion? (Hint validity) — Carmaris19

As @MindForged already told you, you are misusing the term "validity." A valid conclusion is a conclusion that is reached by following (some) rules of logic. Logic itself cannot be valid or invalid.

Scientific impossibility is logical impossibility in the following sense: If it is the case that I am sitting at a table, then it is logically impossible for it to be the case that I am not sitting at a table (within the same context where the first proposition is true). A scientific theory constrains the world to behave in certain ways, and not others. The logical corollary of that is that if you accept the theory (within some domain of application), then you cannot at the same time accept any proposition that (within the same domain of application) violates the constraints imposed by the theory, on pain of being logically inconsistent.

Now, that answers the narrow question. The closely related wider question is: What is the nature of scientific theories, or the laws of nature, as they traditionally have been called? How are we to make sense of the rules and constraints that they posit? That is a huge topic with a wide variety of views.

Is it right that the idea is that the contradiction lies in what the person who drew the maps believes? That is, he believes both A and Not A. If so, I don't think the example really works. The content of my beliefs is contradictory, but there is still no actual state of affairs that is incoherent, is there? — PossibleAaran

Mental maps (and beliefs) are abstract representations of the world. We know that representations can be mistaken or inconsistent. But the maps are not the territory. — Andrew M

States if affairs or physical objects cannot be either coherent or incoherent. It is beliefs, mental maps, or what have you, that can have such a quality as coherency.

Yes, sorry :grimace:

Does the spherical Earth cast doubt upon Popper’s claims about scientific theories never been confirmed? — Craig

Confirmation is what happens when your confidence in a proposition or a theory increases in response to evidence. To deny that our confidence in the proposition that the Earth is round has ever changed, despite everything we have learned, is to deny reality.

Popper goes through ridiculous contortions to deny "confirmation," but in the end he is not actually saying anything different - he just says it more obscurely.

Do people say "time nowadays"? I googled the phrase, and although there are many hits, the sentence context is usually something like "...waste of time nowadays..." or "...time. Nowadays..."

That’s a very aggressive stance you have there. I’m not an authority on his mental health, what’s the diagnosis? — AngryBear

Crackpottery is not a diagnosis - well, not necessarily - it is loopy pseudoscience in this case. Whether the guy really is off his rocker or whether he is just peddling this crap in a bid to make some money is really none of my concern. And I wasn't being aggressive - on the contrary, just wanted to give you some well-intentioned advice. When someone sees you citing a crackpot, they might think: "This person is not to be taken seriously. I better not waste my time listening to what he has to say."

considering the surge of popularity attributed to both Kuhn and Feyerabend (who where fierce anti-Popperians). I wouldn't say it's a banality. — Pelle

I didn't say all of Popper's ideas about science were banal - some of them were just wrong (kidding!) No, I was referring to ideas like "people trying to falsify eachother's theories" and other pop-Popperianisms that some people, including scientists, swear by. Popper's actual lasting impact on the philosophy of science is far more dubious than his rock-star fame would suggest.

Laird Scranton — AngryBear

He is a crackpot. You really don't want to bring this kind of crap into a philosophical discussion - it destroys all credibility.

Yes I understand Nietzsche is one of the hardest Philosphers to read and understand and congrats to all of you for you impeccable knowledge but some of you do come across as quite brash to someone who is just starting out. I am a mature student who has only recently been granted full use of her eyes over these last two years and I have a thirst for knowledge on the subject of Philosophy. I have chosen Nietzsche because I feel for what I have read so far that he is very misunderstood. — Helen G

Well, one thing Nietzsche is not is clear and consistent, which is why just about every scholar of Nietzsche thinks that he is misunderstood by someone (or even everyone) else. So, you are in a good company.

modern science does follow Popper's ideas to some extent. The critical discussion around science today is exactly as Popper described: people trying to falsify eachother's theories. — Pelle

This is a banality.

The ideas that are popularly credited to Popper have been around since Bacon. What is right about Popper's prescriptions isn't new or radical at all.

I would maintain that at least the law of non-contradiction is indubitable in just this sense: it cannot intelligibly be doubted. — PossibleAaran

Yes, even the law of non-contradiction can be intelligibly doubted: see Dialetheism

The a priori status of logic has been under attack for quite some time (as you can see above, even the sacrosanct non-contradiction is not safe). This is true even of the so-called "laws of thought," which is what you must really mean when you talk about logic, because formal or mathematical logic is as diverse and open-ended as mathematics.

Well, in this set up, we don't know anything about the relationship of odd and even, and we don't know anything about prime factorisations or that even means 'is divisible by 2 with no remainder'... The only premise here which is even related to even numbers and squares of even numbers is (1). — fdrake

Either you understand what is written, or you don't. If you don't, then nothing more can be said. If you do, then you know what "odd" and "even" mean. (But then if you do, you don't really need to go through this logical exercise in order to prove the conclusion - you could prove it by other means.)

I thought it was invalid because it seemed a lot like affirming the consequence to me. If you focus on the 2nd premise, — Ulrik

So the question becomes, can we conclude the statement: 'If the square of a number is even, then that number must be even' from the statement 'if a number is even, then its square must be even'? — fdrake

Why are you focusing on the second premise alone when two premises are given?

I don't know. It seems to me that only a defeasible statement can be meaningfully tested. How do you test a tautology (or a contradiction)?

I am familiar with this thought experiment, but not well-versed in its detailed treatment in the literature. I wonder how much of a point of contention this particular issue is. — Arkady

There seem to be quite a lot of references to the thought experiment in the literature - mostly it is (quite extensive) literature on thought experiments in general, but there are some specific examinations of Galileo's thought experiments, including some critical ones.

I found this paper interesting: D Atkinson, J Peijnenburg, Galileo and prior philosophy (2004)

They argue against the idea that Galileo succeeded in giving, in J. Brown's words, a "destructive" (against Aristotle's law of motion) and a "constructive" (in favor of Galileo's alternative) logical argument. Interestingly, they point to case where Aristotle happens to be right! It is the case of terminal velocity, which, under some conditions and idealizations, is directly proportional to the mass of the falling body. And yet Galileo would have it that this is logically impossible. How could that be?...

Somehow I feel I have been deprived of the epiphany I expected, reading the title. — Pair o'Ducks

Yeah, the title is odd: it's supposed to sound provocative, but how is what it ostensibly asserts even controversial?

The author's thesis is stronger than that: he argues that atheism was a "thing" in the ancient world, not just a few individual exemplars.

The "study" is actually a book:

Tim Whitmarsh, Battling the Gods: Atheism in the Ancient World. New York: Alfred A. Knopf, 2015.

Here is the author's presentation: Battling the gods

And a (favorable) review from a classicist: Bryn Mawr Classical Review 2016.06.20