In the seventeenth century, the philosopher and mathematician Rene Descartes pointed out that the communication systems of anomals are qualitatively different from the language used by humans:
It is a very remarkable fact that there are none so depraved and stupid, without even excepting idiots, that they cannot arrange different words together, forming of them a statement by which they make known their thoughts; while, on the order hand, there is no other animal, however perfect and fortunately circumstanced it may be, which can do the same.