The learning of most philosophers is like the learning of children.
Vast erudition results less in the multitude of ideas than in a multitude of images.
Dates, names, places, all objects isolated or unconnected with ideas are merely retained in the memory of the signs, and we rarely recall any of these without seeing the right or left page of the book in which we read it, or the form in which we saw it the first time. Most science was of this kind till recently.