are simulated via what is at the ground-floor level, namely, the fundamental differ-
ence in mode of being.
Ontological pluralism provides a framework for new theories concerning the
nature of time and the nature of persistence.
3.8 How Do We Know We Are Present?
According to PEP, past existents are not non-entities, but rather enjoy a fundamen-
tally different mode of being than presently existing things. This might seem to
generate a skeptical puzzle: how can I know that I am present rather than past? Abe
Lincoln believes that he is present; I believe that I am present. Doesn’t Abe Lincoln
have the same evidence that he is present as I have that I am present? Wouldn’tit
seem to me exactly the same if I were past rather than present? In which case, on what
grounds may I conclude that I am present rather than past?
PEP is not the only view that appears to generate these worries.^61 Any view that
admits a kind of ontological distinction between persons seems as apt to generate
them; examples of such views include a version of modal realism in which possible
people are different in kind from actual people and a type of Meinongianism in
which there are non-existent people. This is not to say that each of these views will be
equally successful in responding to these worries, or that a solution suitable given one
of these views is also suitable given one of the others.
The worries seem most vivid for versions of PEP that hold that past objects and
actual objects can enjoy the same kinds of properties in the same kind of way.
Consider the following line of thought. I know that I am seeing something red
right now. But Abe Lincoln doesn’t, because he doesn’tflat-out know anything.
Instead, he bears determinates of the knows-P-at relation to some times. Since
Iflat-out know many things, and Abe Lincolnflat-out knows nothing, my evidence
base is radically different from Lincoln’s. I actually have evidence (flat-out!) for
various claims, and only presently existing things do. Moreover, Abe Lincoln doesn’t
even believe that he is present, whereas I do; instead, there are times at which Abe
Lincoln bears the believes-he-is-present-at relation.^62 Perhaps these versions of PEP
should be untroubled by our worries. Let’s focus on versions of PEP for which the
worry seems most vivid.
In what follows, I’ll focus onfive kinds of responses to the worry. I’ll call these
responsesacceptance,the phenomenological response, the easy knowledge response,
the appeal to theoretical virtue, andthe indexical response.I’ll discuss them in turn.
(^61) See Merricks (2006) for a development of these worries.
(^62) Forrest (2004) argues that past people lack consciousness; it is a consequence of the view sketched
here that something like this view is correct, but merely as a consequence of a more general view about the
kinds of features that past things can enjoy.