zero-temporal distance from the present, has the highest (logically) possible degree of exist-
ence.... There is a difference of degree and not of kind between the present and what is no
longer present or not yet present. [Smith 2002: 119–20]
While PEP says that past existence and present existence are different kinds
of existence, Degrees Presentism claims that they are merely different degrees of
existence. Overall, I think PEP is the better theory, and in what follows I will
explain why.
We have seen how one can make sense ofways of being, but how should one make
sense ofdegreesof existence? There are two options: define the notion or take it as
primitive. One might try to definedegrees of existencedirectly in terms of concepts
other thanbeingormode of being. For example, one might definex has more
existence than yasy modally depends on x but x does not modally depend on y.^20
Or one might definex has more existence than yasx has more causal power than y.
(More sophisticated definitions could be offered.) Note that neither definition is
promising for the temporal case. Defining degrees of reality in terms of modal
dependence gets things backwards: I am modally dependent on my parents, and
they are dependent on my grandparents, and so on. But my great-grandparents are
not modally dependent on my grandparents, nor are my grandparents dependent on
my parents, and so on. So, on this way of defining degrees of reality, my great-
grandparents enjoy a higher degree of existence than I enjoy, even though I am
present and they are past. Similarly for definitions that appeal to causal power. The
Big Bang that began the universe had more causal potency than I ever will, and yet it
is past and I am present. One way of defining the notion of degrees of reality gets the
right result but at the cost of utterly trivializing Smith’s view:xexists to a greater
degree thany= df.xis closer to the present moment thany. (The B-theorist could
accept this definition and then say that the past is less real than the present!) It seems
to me that none of these ways of thinking of degrees of existence is really about
existence; rather, they are about different subjects that are discussed in old but inapt
terminology.
This is not to say that these are the only plausible ways of understanding“degree of
existence.”In chapter 5, I will define a notion of degree of existence in terms of
relative naturalness of quantifiers. And in chapter 7, I will discuss whether this notion
of degree of existence should rather be taken as primitive and used to define up a
notion of naturalness instead!^21 But for Smith’s purposes, the notion of degree of
existence that I will discuss in chapters 5 and 7 is inadequate, since the nature and
existence of the things that are fully existentfix the nature and existence of the things
(^20) xmodally depends onyjust in case any possible world in whichxexists is one in whichyexists.
(^21) These are not the only proposals, either. Tim Perrine has suggested to me a proposal on which
existence is afirst-order property and instantiation comes in degrees. I’m not opposed to degrees (or
modes) of instantiation, but I hope to explore in future work how these could be captured using degrees
(and modes) of being, and so will not pursue this interesting suggestion further here.