Is ecology at a crossroad? After three decades of rapid, though somewhat anarchic development, many ecologists now are beginning to ask this question. They have the feeling of no longer belonging to a unified and mature scientific discipline. Many of them claim to be mere empiricists, whereas others are proud to be considered theoreticians. Each side has its own journals and holds its own specialists' meetings, tending to disregard the achievements of the other. The communication gap between the two schools is quickly widening, to the detriment of both. To make things worse, the word...