Unlimited tolerance must lead to the disappearance of tolerance. If we extend unlimited tolerance even to those who are intolerant, if we are not prepared to defend a tolerant society against the onslaught of the intolerant, then the tolerant will be destroyed, and tolerance with them. In this formulation, I do not imply, for instance, that we should always suppress the utterance of intolerant philosophies; as long as we can counter them by rational argument and keep them in check by public opinion, suppression would certainly be most unwise. But we should claim the right to suppress them if necessary even by force; for it may easily turn out that they are not prepared to meet us on the level of rational argument, but begin by denouncing all argument; they may forbid their followers to listen to rational argument, because it is deceptive, and teach them to answer arguments by the use of their fists or pistols. We should therefore claim, in the name of tolerance, the right not to tolerate the intolerant. We should claim that any movement preaching intolerance places itself outside the law, and we should consider incitement to intolerance and persecution as criminal, in the same way as we should consider incitement to murder, or to kidnapping, or to the revival of the slave trade, as criminal.

–Karl Popper

Critical rationalism

Against Bohr's instrumentalism, support Einstein's realism.

Let us say that, in general, failure (and disconfirmation) are more informative than success and confirmation, which is why I claim that negative knowledge is just "more robust".

Now, before starting to write this section, I spent some time scouring Popper's complete works wondering how the great thinker, with his obsessive approach to falsification, completely missed the idea of fragility. His masterpiece, The Poverty of Historicism, in which he presents the limits of forecasting, shows the impossibility of an acceptable representation of the future. But he missed the point that if an incompetent surgeon is operating on a brain, one can safely predict serious damage, even the death of the patient. Yet such subtractive representation of the future is perfectly in line with his idea of disconfirmation, its logical second step. What he calls falsification of a theory, in practice, to the breaking of the object of its application.

In political systems, a good mechanism is one that helps remove the bad guy; it's not about what to do or who to put in. For the bad guy can cause more harm than the collective actions of good ones.

–Nassim Taleb

Karl Popper's idea that theories can be definitely falsified, but never definitely confirmed, is yet another special case of the Bayesian rules: if p(X|A) ~ 1, if the theory makes a definite prediction, then observing !X very strongly falsifies A. On the other hand, if we observe X, this doesn't definitely confirm the theory, there might be some other condition B such that p(X|B) ~ 1, in which case observing X doesn't favor A over B. For observing X to definitely confirm A, we would have to know, not that p(X|A) ~ 1, but that p(X|!A) ~ 0, which is something that we can't know because we can't range over all possible alternative explanations. For example, when Einstein's theory of General Relativity toppled Newton's incredibly well-confirmed theory of gravity, it turned out that all of Newton's predictions were just a special case of Einstein's predictions.

–Eliezer Yudkowsky

Stephen Hawking erroneously referred to Popper as positivist:

Any sound scientific theory, whether of time or of any other concept, should in my opinion be based on the most workable philosophy of science: the positivist approach put forward by Karl Popper and others. According to this way of thinking, a scientific theory is a mathematical model that describes and codifies the observations we make. A good theory will describe a large range of phenomena on the basis of a few simple postulates and will make definite predictions that can be tested. … If one takes the positivist position, as I do, one cannot say what time actually is. All one can do is describe what has been found to be a very good mathematical model for time and say what predictions it makes.

However, the claim that Popper was a positivist is a common misunderstanding that Popper himself termed the "Popper legend".[55] In fact, he developed his beliefs in stark opposition to and as a criticism of positivism and held that scientific theories talk about how the world really is, not, as positivists claim, about phenomena or observations experienced by scientists.[56] In the same vein, continental philosophers like Theodor Adorno and Jürgen Habermas regarded Popper as a positivist because of his alleged devotion to a unified science. However, this was also part of the "Popper legend"; Popper had in fact been the foremost critic of this doctrine of the Vienna Circle, critiquing it, for instance, in his Conjectures and Refutations.

What links here

• Imre Lakatos (1922–1974)
• Knowledge production
• "Analytic philosophy"
• Meta-science
• Timeline of people born
• Logical positivism

Not to be confused with Bruno de Finetti.

Took the Copernican model and extended it to propose that the stars are distant suns surrounded by their own planets (correct), and raised the possibility that they could foster life of their own.

Tried for heresy by the Inquisition on charges including "denial of eternal damnation, the Trinity, the divinity of Christ, the virginity of Mary, and transsubstatiation". Also "of concern" was his pantheism and his teaching of reincarnation. He was burned at the stake.

What links here

• Astronomy
• Timeline of people born

This was triggered by the discussion on news.ycombinator.com/item?id=5305055.

I feel that much of the perceived difference between modefulness and modelessness is in your head (doesn't make it less real, I admit). Look, are you familiar with the concept of a hotkey sequence? They're the most visible in Emacs, where many commands are bound to a sequence such as C-x C-s.

Everything we do on a keyboard is part of a sequence. In Vim, you can type :wqa to execute a command, and if someone made a similar binding in Emacs, it would be represented in their notation as S-; w q a, and more importantly, it would feel different to many people. Because in Vim, : makes you enter a state where you can type anything you want in a free-input field, and in this case you type wqa. In Emacs, pressing S-; will make the minibuffer display S-; while nothing happens, indicating that you've begun a hotkey sequence. As you press each key, they'll show up: S-; w q a … It feels like you're in the same state throughout, where Emacs is doing nothing and waiting for you to reach a sequence that is bound to a command. In particular, you feel constrained. In the Vim equivalent, you can backspace whereas in Emacs if you press the wrong key you have to re-do the sequence.

But you're ultimately doing the same thing with your fingers. Someone recording your fingers wouldn't know if you were executing an Emacs command, a Vim command, or merely typing ":wqa" into the body of a blog post.

When you type the word "hi", you are executing the sequence of pressing the h key followed by the i key. I grant this is a silly example, but I need to show that every keystroke comes in sequences. Sequences are the universe, the backdrop of everything that happens during keyboard input.

Modern editors typically have hotkey sequences consisting of a single step. Obviously, a single hotkey is always better than two in a sequence. By the same token, two hotkeys are better than three, and so on. You want the fewest number of steps in the sequence, for convenience. Cheers to modern editors!

This is complicated by the question of which hotkeys you put in the sequence. If they are single letters like w q a, fine! If they are C-c C-x p, not so good. The latter looks like three keystrokes but is four, or five if you count having to release the Ctrl key before pressing p, which I find at least as annoying as having to press it in the first place.

Now, back to modern editors: they typically have hotkey sequences consisting of a single step. But what hotkeys? Almost always a combination like Ctrl-F, which is two keystrokes minimum.

Given that they're modeless, of course they have to do it this way. And it's not so bad. The thing about Vim Normal mode is that single-hotkey commands don't even need modifiers, you can just press f, no Ctrl.

The drawback is that you have to enter a "mode", which sounds weird.

To get around this, I will describe another basic concept of keyboard input, which has many names but that I'll call a hydra. A hydra is a many-headed beast of Greek myth, that grew new heads whenever one was cut off. It's also a way of making hotkey sequences more persistent. For example, suppose that you wanted to execute the following commands:

C-c C-x p
C-c C-x l
C-c C-x a

Lot of work, right? But, if the sequence C-c C-x is a hydra, then what you have to type is

C-c C-x p l a

That is, the first parts of the sequence don't have to be retyped.

The way hydras are typically implemented in Emacs is that they're nonpersistent (compared to a Vim mode, see later). As soon as you hit some key (let's say r) that isn't bound to anything in the hydra, it exits the hydra and does what that key would have done instead, i.e. instead of it trying to execute the equivalent of C-c C-x r you simply type the letter r onscreen. The hydra is exited trivially, unlike modes in Vim that have to be exited with the ESC key.

Now the meat of the topic. All that a mode is, is a type of hydra. The Vim Normal mode is a hydra that starts with ESC, and it's very broad, having many different keybinds coming after ESC. We might say that the hydra has one head for every key on your keyboard: there are none undefined. It's a persistent one, as it's not easy to exit. The escape hatch is the i key, which instead puts you in the Insert mode hydra (and doesn't insert the letter "i": it's a whole keystroke merely to change mode and do nothing more).

If you like to view it this way, all editors are constantly in a hydra, just one that doesn't need to be entered with any key beforehand. Modeless editors aren't modeless, they have one mode.

Now think about this: What is easier to press, Ctrl-F or Ctrl then F? Is it easier to press the D key and the F key at the same time, or to press them in sequence?

YMMV, but many feel that pressing two keys in sequence is more comfortable than two keys at the same time.

So over of pressing d and f together, we always prefer the sequence d and then f. What if the reason you do this is that 'd' puts you in a different mode, where the 'f' key will do what you want? Does it make a difference? In the Vim paradigm, yes: you will also have to exit that mode when you're done. Then it can be preferable to just press a chord such as Ctrl+F and not think about entering and exiting modes.

Suppose the mode wasn't persistent? I.e. suppose by pressing d you enter the mode, then by pressing f, you execute that command and return to the mode you were in previously.

Well. Then it's not a mode as most would define it, just a hotkey sequence. (It can be a hydra though: hydras may have both persistent and non-persistent heads, a mixture of those that grow back and those that don't)

If you want to take the classification to the extreme, each hotkey in a hotkey sequence is a small mode, a non-persistent one, wherein the next hotkey will do something it wouldn't have done otherwise. Emacs has hundreds or thousands of these small modes while Vim has three big modes. Most editors have one (by virtue of rejecting hotkey sequences altogether).

Microsoft Word is actually an exception. If you're a whiz with hotkeys there, you know what I mean: they use hotkey sequences (all of which start with Alt), though never with modifiers. It's like the best of Vim and Emacs: the modes are non-persistent and automatically exit (unlike Vim), and they don't need you to hold down the Ctrl key either (unlike Emacs). The only way to improve on this would be make some of those sequences into hydras, and correct me if I'm wrong, but I think Word has done that too.

Word is bad in so many ways, but it seems the keyboard input was competently designed.

Anyway, I hope modes don't feel weird now.

Keyboard design

What links here

• 2023-09-13