## Sound arguments and rationally convincing arguments

I’ve read many times and places that an argument is sound iff 1.      The argument is valid. 2.      All the premises of the argument are true. [1] Let’s call this the standard definition of a sound argument. Now consider this argument: 1.      If the Earth is a planet, then there is a satellite above Denmark […]

## Stone-paradox – revised and explained

I posted this text a long time ago in Danish and I translated it and used it on the forum. I think I forgot to post the English version here as well. I apologize for the low quality English in the text. – I have earlier written a short article about why the stone-paradox not […]

## XKCD’s NP-Complete

Opening paragraph: “I was reading XKCD along with a friend and we came across a comic. He wanted to continue reading but I wanted to solve it! […]” Extensive mathematical symbols necessitates a PDF file. XKCD’s NP-Complete ETA: Some of the data in the PDF is missing it seems. I do not have a backup.

## Induction and a probability formula

I thought about how induction relates to the probability of something, and I came up with this formula. Induction is here taken as repeated confirming observations of some theory or hypothesis. Formula. When the amount of confirmed observations, O, of a hypothesis goes towards infinity, then the probability of the hypothesis given the observations, Pr(H|O), […]

## Some different deterministic theses

Determinism is a fairly broad thesis, and some formulations of it does not “work” with Swartz’s regularity theory. Below I have outlined some different deterministic theses. Minimal Causal Determinism (MCD): All events are caused. Necessarian Causal Determinism (NCD): “[G]iven a specified way things are at a time t, the way things go thereafter is fixed […]

## Worldviews and mistaken beliefs, a paradox

Here’s a little paradox that I’ve come across while thinking. It’s about worldviews and knowing that at least one thing I currently believe to be true is actually false. The argument 1.      For all x, if x is a belief in my worldview, then I hold that belief. [Premise] 2.      If for all x, if […]

## Meaning, propositions, category errors

I quote Swartz: “What sort of thing is my pen’s  being on my desk? We are inclined to say such things as “My pen’s being on my desk is true,” which would suggest that my pen’s being on my desk is a proposition; but we are also inclined to say such things as “My pen’s […]

## Modal logic formalization, multiple kinds of possibilities

Formatting requires a PDF file. modal-logic-formalization

## The recent controversy about Hume's Maxim against justified belief in miracles

Contrary to what I normally do I’m not going to argue anything in this article. My goal is to spread useful information, mostly in form of links about Hume’s maxim. Hume’s maxim Hume mentions this in his essay An Enquiry Concerning Human Understanding.[i]: 91. The plain consequence is (and it is a general maxim worthy […]

## The term non-sequitur

As Wikipedia notes,i the term is used in everyday speech to deny a conditional (if-then statement), and it is also used in logic to mean an invalid argument. This together with the fact that in normal language people do not write the complete arguments when they argue, makes it very easy to confuse things. Suppose […]