“If you don’t believe Euclid’s proof that there are infinitely many primes, then I don’t know why seeing a formal proof in ZF set theory should quell your doubts. You could deny Modus Ponens, you could demand a formal proof for the assertion “The infinitude of primes is a theorem of ZF” itself (ad infinitum), you could refuse to identify the formal notions of ‘prime’ or ‘infinity’ with the informal ones, and so on.

“Easy things are often simple, and hard things are often complicated. But making a hard thing simple takes skill.

“‘Work’ is usually doing what others tell you to. ‘Life’ is doing what you want. The modern fixation on ‘work-life balance’ becomes irrelevant if you work for yourself.

“These posts are aimed at people who want to excel throughout their careers and make a significant impact on their fields and the world. These posts are not appropriate for people for whom work/life balance is a high priority..

“In order to get tenure you must not arrive at conclusions that members of tenure committees can disagree with. In math and the sciences, you can prove what you’re saying. Or adjust your conclusions so you’re not claiming anything false (“6 of 8 subjects had lower blood pressure after the treatment”). In the humanities you can either avoid drawing any definite conclusions, or draw conclusions so narrow that no one cares enough to disagree with you.

“Ruby, unlike less flexible languages, lets you alter the value of a constant.

“The great lesson of direct mail was that long letters always do better than short ones. That’s because once you’ve sold me, I’ll stop reading. But if I’m not sold and I get to the end, you lose.

It’s okay to be long, if you’re chunky.

“I don’t have time to test on Opera. Sucks to be Opera. Startup web browsers don’t stand a chance.

“If you discover that users are afraid or resistant to what you’re trying to get them to do, more information is almost always the incorrect response. The effective technique involves peer pressure and support.