ARGUMENTS FOR MONOTHEISM 173Unfortunately (something its users do not intend) the language that
contrasts de dicto (of speech) and de re necessity can easily suggest that
there is one thing – say, logical necessity – and another thing – say,
metaphysical necessity – and that the former is relative to language and the
latter, if it exists at all, is a human-mind-independent thing. In fact, those
philosophers who favor the view that there are both necessities de dicto and
necessities de re view things very differently. To speak of the necessity of a
dictum is to speak of the necessity not of an asserted declarative sentence
but of what is asserted by that sentence – of a proposition. Necessarily true
propositions, on their view, are human-mind-independently necessary and
human-mind-independently true. They no more depend for their necessity
or their truth on us than do necessities de re. There are necessities de re
only if there are essences.
One can summarily put the point like this: there are necessarily true
propositions, and if there are essences, some of those necessarily true
propositions will be necessarily true about essences, including some
conditional necessary truths about things that have those essences to the
effect that they necessarily have them if they have them at all. For
example, it is true of Tony that:
B Tony is necessarily a person,
and that:
A* If Tony is necessarily a person, then the proposition If Tony exists
then Tony is a person is a necessary truth.
Proposition B expresses a de re necessity. Proposition A* expresses a de
dicto necessity.
If something X lacks logically necessary existence, then even if it has an
essence E, it is not a logically necessary truth that X has E, because it is not
a logically necessary truth that X exists. What is necessarily true, if thing X
has essence E, is that X has E if X exists.
Assuming they exist at all, necessity de dicto is no less metaphysical
than necessity de re – no less language-and-convention independent, no
less human-mind-independent. There being necessities de dicto does not
require that there are essences; there are necessities de re only if there are
essences. If they exist at all, de re necessities are logical necessities among
things – things including but not limited to propositions. If they exist at
all, de dicto necessities are logical necessities only among things that are
propositions.
A final point on this topic. Suppose that Water is essentially H
2
O is
true. Then Necessarily, water (if it exists) is H
2
O is true. To each necessity