Think for yourself! : Twenty applications of philosophy, by Jens Zontgen

Most of the important philosophers were almost book collectors. For example, Plato, who was a wealthy man, used to buy rare philosophical texts, even sometimes paying huge amounts. Aristotle himself owned a complete library which he gifted after his death to his student Theophrastus. But collecting books is only the external appearance of philosophical collection. Philosophers are "think collectors." Even reading, this old activity of philosophers, is a form of collection. Even today, in German, one can talk about the (Weinlese), meaning grape harvesting and gathering, and one of these types of harvesting or gathering is reading a book; the reader wanders through the lines and pages as if wandering through a vineyard, collecting mental and spiritual fruits here and there.