I think the definition of a book is changing.

Classic' - a book which people praise and don't read.

Why is The Origin of Species such a great book? First of all, because it convincingly demonstrates the fact of evolution: it provides a vast and well-chosen body of evidence showing that existing animals and plants cannot have been separately created in their present forms, but must have evolved from earlier forms by slow transformation.

Writing a long and substantial book is like having a friend and companion at your side, to whom you can always turn for comfort and amusement, and whose society becomes more attractive as a new and widening field of interest is lighted in the mind.

It was great fun writing a book.... It built an impalpable crystal sphere around one of interests and ideas. In a sense one felt like a goldfish in a bowl; but in this case the goldfish made his own bowl. This came along everywhere with me. It never got knocked about in travelling, and there was never a moment when agreeable occupation was lacking. Either the glass had to be polished, or the structure extended or contracted, or the walls required strengthening.

Writing a book is an adventure. To begin with it is a toy and an amusement. Then it becomes a mistress, then it becomes a master, then it becomes a tyrant. The last phase is that just as you are about to be reconciled to your servitude, you kill the monster and fling him to the public.