Fine - guide to ground.pdf - Ted Sider

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at best, mediately grounded in statements about atoms. It is the notion of immediate ground that
provides us with our sense of a ground-theoretic hierarchy. For given any truth, we can take its
immediate grounds to be at the next lower level. Thus as long as mediate grounds are always mediated
through immediate grounds, any partial ground for the truth will always be at some finite level below
the level of the truth.
Weak/Strict Ground
The fourth distinction, between weak and strict ground, is less familiar still. Ground in the
previous sense is strict and does not allow a truth to ground itself, while ground in the weak sense
allows - and, indeed, requires - that a truth should ground itself.
We might perhaps express weak ground by means of the locution ‘for - and for - and ... is for -’,
where the last ‘for’ specifies the statement to be grounded and the first ‘for’’s specify its grounds. Thus
for John to marry Mary is for John to marry Mary, for John to marry Mary is for Mary to marry John,
and for John to marry Mary and for Mary to marry John is for John to marry Mary. Or to take a
somewhat different example, for Hesperus to be identical to Phosphorus and for Phosphorus to be a
planet is for Hesperus to be a planet (in this case, it might be argued that, in contrast to the others, the
grounded truth does not weakly ground any of its grounds).
What is characteristic of these cases is that any explanatory role that can be played by the given
truth can also be played by their grounds. Thus if John’s marrying Mary accounts for the existence of
the married couple John and Mary, then Mary’s marrying John also accounts for the existence of the
married couple. Or if John’s marrying Mary accounts for John’s marrying Mary or Bill’s marrying Sue
then Mary’s marrying John will also account for John’s marrying Mary or Bill’s marrying Sue.
We might think of strict ground as moving us down in the explanatory hierarchy. It always
takes us to a lower level of explanation and, for this reason, a truth can never be strict ground for itself.