Addendum to "Two Kinds of Existences?"

Traditional Questions about Existence

• A Brief History -

[There was not enough room to include this in the original posting.]

Here is a, slightly biased, view of the history of how philosophy addresses the question of existence. It is based on the article on Existence given in the Stanford Encyclopedia of Philosophy. (https://plato.stanford.edu/entries/existence/)

Questions about existence are motivated by several issues. Here are two:

(1) Ontological Argument for God
God must exist. God is the most perfect thing in the universe. The most perfect thing must have all the best properties. Existence is one of the best properties. Hence, God must exist.
(2) Statements about things that do not exist
How can we make statements about things that do not exist? First example: Consider: “The present king of France is bald”. Is this statement true or false? If you say it is false, you are committed to asserting there is a king of France (which is not true) and this fictitious person is bald. If you say it is true, you are making a false statement because there is no king of France. Second example: What does it mean to say that God does not exist? If God does not exist, then what is the referent for the word ‘God’?

Throughout Western history, many famous philosophers have agreed with Aristotle (Hume, Kant, Frege, Russell) “in denying that existence is a property of individuals.” Frege and Russell, in addition to maintaining that existence is not a property of individuals, also held that it was a “second-order property”. For Frege this meant that existence was a “concept”. For Russell this meant that existence was a “propositional function”.

Here is the solution proposed by Frege and Russell: To say that unicorns do not exist is to say the property of being a unicorn is not instantiated (i.e. there is no concrete example where something has the properties associated with a unicorn). To say that unicorns do exist is to say the property of being a unicorn is instantiated (i.e. there are concrete examples where something has the properties associated with a unicorn). Curiously, the famous Austrian philosopher Meinong (1853 – 1920) held that there is a distinction between being and existing. He maintained existence is a property of individuals. Universals may not 'exist', but he wanted them to have some kind of 'being'. Meinong is famous today because he was the first writer to demonstrate the importance of intentionality in the philosophy of mind.

Ever since the beginning of the twentieth century, most philosophers have adopted Russell’s view toward existence. The main reason for this is probably due to the success of predicate logic (mathematical logic, predicate calculus, logic of quantifiers, first-order logic) which incorporates his ideas about existence. Today, predicate logic is used in mathematics, philosophy, linguistics, and computer science.

There is another historically interesting reference to two kinds of existences. In Plato’s Phaedo, he distinguishes between the everchanging, visible world that we experience and the unchanging world of forms. This distinction is different from the one drawn between those things that have an objective third-person existence and those things that have a subjective first-person existence. Plato’s distinction is probably more relevant to the philosophy of science than the philosophy of mind. Scientists, like Pato, distinguish between the raw uninterpreted phenomena and the principles of physics that capture the universal patterns in the phenomena. The existence of Plato’s forms seems to be similar to the being of Meinong’s properties.

• Ron Willig