The single greatest edge an investor can have is a long-term orientation.

As Graham, Dodd and Buffett have all said, you should always remember that you don't have to swing at every pitch. You can wait for opportunities that fit your criteria and if you don't find them, patiently wait. Deciding not to panic is still a decision.

It sounds kind of crazy, but in times of turmoil in the market, I've felt a sort of serenity in knowing that I've checked and re-checked my work, one plus one still equals two regardless of where a stock trades right after I buy it.

Things that have never happened before are bound to occur with some regularity. You must always be prepared for the unexpected, including sudden, sharp downward swings in markets and the economy. Whatever adverse scenario you can contemplate, reality can be far worse.

We are not so brazen as to believe that we can perfectly calibrate valuation; determining risk and return for any investment remains an art not an exact science

A tipping point is invisible, as we just saw in Greece. In most situations, everything appears fine until it's not fine, until, for example, no one shows up at a Treasury auction.

Most investors are primarily oriented toward return, how much they can make and pay little attention to risk, how much they can lose.