Some interesting information there, thank you. But what, really and truly, is knowledge? Are there many things which must be known in order to comprehend the world, or is there just one thing? Which of the great men and women of history knew that one thing that is the fount of all subordinate knowledge? Today, we do not need to carry particular knowledge around in our heads, because we have tools that do the job for us. And we surely do not need particular knowledge if we know that one thing that really matters.