Existence of 100 dollars is greater than non-existence of 100 dollars especially if I want to buy something. This example of existence improving the concept can be repeated in many areas. The concept of holding your own baby as compared with actually doing it In all these examples existence has improved upon the concept. This is not because the concepts were inadequate or incomplete. We find even after attending the symphony for many years, the concept in our mind is not equal to actually listening to the musicians.
Existence makes a difference.
Therefore it must be a property. To deny existence as a predicate is absurd. I would like to conclude this discussion of existence as a predicate with a look at a typical philosophy textbook argument explaining Kant's position. Dogs bark and 2. They then compare 1a.