“The Hering illusion looks like bike spokes around a central point, with vertical lines on either side of this central, so-called vanishing point. The illusion tricks us into thinking we are moving forward, and causes the visual cortex to try to extrapolate to the future. Since we aren’t actually moving and the figure is static, we misperceive the straight lines as curved ones.

“The conversations you overhear tell you what sort of people you’re among.

“Bad elevator pitches go on and on about the product. Good ones boil it down to a high concept pitch. The rest of the elevator pitch should be devoted to your traction, social proof, team, and market.

“A fanatic redoubles his efforts when he has forgotten his aim.

“The power output of a supernova is ‘bounded’, but I wouldn’t advise trying to shield yourself from one with a flame-retardant Nomex jumpsuit. Don’t make the leap from “This is ‘bounded’” to “The bound must be a reasonable-looking quantity on the scale I’m used to.”

“The importance of always identifying the source lies not only in common justice, but in truth to life. Whether we like it or not, individuality is the product of our collective existence.

In the matter of style, freedom lies in all the ways we have been a prisoner of someone else’s example.

“To a mathematician all structures are static. In the hands of a mathematician, the Peano axioms create the integers without reference to time, but if a computer scientist uses them to implement integer addition, he finds they describe a very slow process.

“Excellence comes from lots of ordinary habits — selecting them, accreting them over time, and developing them with discipline.

Different levels of achievement reflect vastly different habits, values, and goals.

The notion of talent is useless and tends to mystify excellence.

“The price of total personalization is total transparency.

“Obama’s campaign has been in the doldrums for the past few months. He’s never come up with an explanation about how he would actually transform politics, and his conventional substance is beginning to overshadow his unconventional style. But Obama still seems like a human being. He still seems to return each night to some zone of normalcy where personal reflection lives. He wasn’t fully candid when answering questions about the Rev. Jeremiah Wright, but there are some inner guardrails that prevent the spin from drifting too far from the truth. Thoughtful and conversational, he doesn’t seem to possess the trait that Clinton has: automatically assuming that critics are always wrong.

Obama still possesses his talent for homeostasis. His astounding composure has come across as weakness in the midst of combat with Clinton, but it’s also at the core of his promise to change politics. He vows to calm hatred and heal division.