Notes about logic

From Lewis Carroll’s Symbolic Logic, which aimed to make logic understandable via quirky syllogisms and illustrated tables:

1. No interesting poems are unpopular among people of real taste;
2. No modern poetry is free from affectation;
3. All your poems are on the subject of soap-bubbles;
4. No affected poetry is popular among people of real taste;
5. No ancient poem is on the subject of soap-bubbles.

Conclusion: all your poems are uninteresting.

From Nature’s review (sorry about the academic paywall) of the new book Not Exactly: In Praise of Vagueness:

Although scientists strive for increasing clarity in their measurements and concepts, it is often uncertainty that spurs new thinking. The haziness of the species notion set the young Charles Darwin pondering evolution. Francis Crick observed that if he and James Watson had worried about how to define the gene in the 1950s, progress in molecular biology would have stalled. “In research the front line is almost always in a fog,” Crick wrote in his autobiography. Even today there is no consensus definition of the gene.

Another excerpt:

“Sometimes,” confesses the computer scientist Kees van Deemter, “one just has to be sloppy.”