[196] English nominalism^a became powerful in the 18th century and were very willing to receive those elements of nominalism which came from the Continent in our century, especially the school of Vienna,^b which produced the large movement of symbolic logic, and logical positivism^c generally. Now this situation has consequences for the whole philosophical discussion in the Western world today. Let me first tell you what the main point is. The question is whether there are only individual trees or whether treehood, the quality of BEING a tree, has an ontological standing, a "BESIDES" the individual tree. REALISM^d in the Middle Ages means that the universals^e have some kind of reality. Certainly, they do not have the kind of reality which the individual things have; they are not a second world beside the given world. But they have the reality of determining the growth of every tree into the eidos, the image, of a tree. This was called realism. To make the understanding easier for you, what was called realism^f in the Middle Ages is usually called idealism today. The meaning of the words has turned around almost 180°. The reason for this is an interesting problem of the history of philosophical thought, but l cannot go into it now. In any case, the question remains very much alive. And today the discussion is going on between logical positivism^g and ontology.^h Now it's obvious that in this discussion, a lot of philosophical arguments can be used. They have been used as early as in the later period of the Platonic school, of Platoⁱ's life himself, when Aristotle^j argued against Plato's ontological realism and brought out most of the later arguments for nominalism, ^kalthough he himself was not a nominalist at all. Since that time, the problem never came to rest, and today, when some people defend ontological ^lquestions and others deny that these