Encyclopedia as a Directory of Associations

Every science overlaps with others: they are two continuous branches off a single trunk. He who composes an opus does not enter abruptly into his subject, does not close himself strictly within it, does not leave it abruptly: he is obliged to anticipate terrain adjoining his; its consequences often take him onto another contiguous terrain on the opposite side; and how many other excursions are necessary in the body of the work? What is the purpose of the forewords, introductions, prefaces, ex...