(Roughly) Daily

xkcd

The principle of explosion (ex falso sequitur quodlibet*), a law of classical logic, asserts that “anything follows from a contradiction”– that’s to say, once a contradiction has been asserted, any proposition (or of course, its opposite) can be inferred from it. Symbolically, that’s:

Readers may be relieved to know that two different models of paraconsistent logic allow for contradiction without explosion.

* “from falsehood/contradiction follows what pleases”

As we revisit our debate strategies, we might recall that it was on this date in 1869 that Dmitri Mendeleev presented the first periodic table of elements to the Russian Chemical Society.  Mendeleev’s chart captured the known elements of the day, and allowed him to predict the properties of elements yet to be discovered.

Mendeleev and his chart, memorialized in St. Petersburg