The reader will understand that calculus is not all sweetness and light. There is
work to do. You absolutely have to solve problems—and think carefully. As one of
my students said, “My God, I have to read the words.” I guess that's true, and I hope
the words come to the point. The book will try not to waste your time. Its object is
not to “cover” material, but to uncover and explain it. In the end, teaching a subject
comes down to teaching a person.

The heart has two eyes to perceive that which is not visible to the eye. One is the 'Sun Eye', which sheds a bright light on our understanding of things from a rational and logical perspective. The other is the 'Moon Eye', which perceives things through instinct or emotion, in our imagination or dreams. Both eyes exist in our hearts.

The Earth goes around.
We gaze at the moon, illuminated by the sun.
Feet on the ground and facing the sky, we go forward, changing as we do.
In order to deliver a larger truth to the person looking down at an open page.

You might ask why we cannot teach physics by just giving the basic laws on page one and then showing how they work in all possible circumstances, as we do in Euclidean geometry, where we state the axioms and then make all sorts of deductions. (So, not satisfied to learn physics in four years, you want to learn it in four minutes?) We cannot do it in this way for two reasons. First, we do not yet know all the basic laws: there is an expanding frontier of ignorance. Second, the correct statement of the laws of physics involves some very unfamiliar ideas which require advanced mathematics for their description. Therefore, one needs a considerable amount of preparatory training even to learn what the words mean. No, it is not possible to do it that way. We can only do it piece by piece.