Context: Plants are one of the two groups into which all living things were traditionally divided; the other is animals. The division goes back at least as far as Aristotle (384 BC -- 322 BC), who distinguished between plants, which generally do not move, and animals, which often are mobile to catch their food. Much later, when Linnaeus (1707 -- 1778) created the basis of the modern system of scientific classification, these two groups became the kingdoms Vegetabilia (later Metaphyta or Plantae) and Animalia (also called Metazoa). Since then, it has become clear that the plant kingdom as originally defined included several unrelated groups, and the fungi and several groups of algae were removed to new kingdoms. However, these organisms are still often considered plants, particularly in popular contexts.

Question: who divided up the living world into just plants and animals?
Steam of consciousness below:
The relevant sentence in the passage is: The division goes back at least as far as Aristotle (384 BC -- 322 BC), who distinguished between plants, which generally do not move, and animals, which often are mobile to catch their food.
So, the answer is Aristotle.