It is part of our everyday life that we ascribe beliefs, desires, hopes, claims, predictions and so on to other people and ourselves, and the ascription of such propositional attitudes, as they are called, generally takes a canonical form, of the sort John believes that Macron is president of France, Mary hopes that Macron is president of France, and Joe predicted that Macron would become president of France.
What makes something we see or something we talk about a single thing, or simply a unit that we can identify and that we can distinguish from others and compare to them? For ordinary objects like trees, chairs, mountains, and lakes, the answer seems obvious.
One of the most striking features of natural language is that it comes with a wealth of terms for abstract objects, or so it seems, and to a great extent they can be formed quite systematically and productively. First, we can form nominalizations from expressions that normally serve as predicates, for example adjectives, and the nominalizations can be used, it seems to refer to abstract objects.
Sometimes when looking at some piece of reality, puzzling choices have to be made when describing it as ‘one’, as ‘many’ or perhaps as neither ‘one’ nor ‘many’. Three woodblock prints of the artist Hokusai can illustrate the issue.