Validity and necessary truths
Validity is defined in a couple of ways. I like to define it like this: An argument is valid iff the superconjunction1 of all the premises and the negation of…
Truth tables and necessary truths
In the essay Validity and necessary truths I used truth tables with necessary truths and impossibilities in it. I did it like this: P □Q P→□Q T T T F…
Quote of the day: Jake "Leaf" Greenleaf
Concerning a formal debate with a theist: "I'm not telling the theist how to affirm, I'm saying how to present it. A numbered list of premises, inferences and a conclusion…
Logical impossibilities
What does impossible mean? Other than 'not-possible'. Logical impossibility is the topic of this essay. More specifically we're going to explore the two distinct meanings of logical impossible that I…
Some modal fallacy whine
Given how much debate the modal fallacy have spawned on FRDB, it's interesting to note how little two academics wrote about it when they encountered it while discussing knowledge skepticism:…
Definition of 'a probability'
A probability is something that is more than a mere logical possibility. I also think that it is stronger than a mere physical possibility (I'm a regularity theorist). Here's one…