of its existence. This "_law of sufficient_ (or _determinant)
reason_"[568] is the fundamental principle of all metaphysical inquiry.
It is contained, at least in a negative form, in that famous maxim of
ancient philosophy, "_De nihilo nihil_"--"Adynaton ginestai ti ek
medenos prouparxontos." "It is impossible for a real entity to be made
or generated from nothing pre-existing;" or in other words, "nothing can
be made or produced without an efficient cause."[569] This principle is
also distinctly announced by Plato: "Whatever is generated, is
necessarily generated from a certain aitian"--_ground, reason_, or
_cause_; "for it is wholly impossible that any thing should be generated
without a cause."[570]

[Footnote 566: "Phaedo," Sec. 103.]

[Footnote 567: _Suppono_, to place under as a support, to take as a
ground.]

[Footnote 568: This generic principle, viewed under different relations,
gives--

1st. _The principle of Substance_--every quality supposes a subject
or real being.

2d. _The principle of Causality_--every thing which begins to be
must have a cause.

3d. _The principle of Law_--every phenomenon must obey some uniform
law.

4th. _The principle of Final Cause_--every means supposes an end,
every existence has a purpose or reason why.

5th. _The principle of Unity_--all plurality supposes a unity as
its basis and ground.]

[Footnote 569: Cudworth's "Intellectual System," vol. ii. p. 161.]

[Footnote 570: "Timaeus," ch. ix.]

The first business of Plato's dialectic is to demonstrate that the
ground and reason of all existence can not be found in the mere objects
of sense, nor in any opinions or judgments founded upon sensation.
Principles are only so far "first principles" as they are permanent and
unchangeable, depending on neither time, nor place, nor circumstances.
But the objects of sense are in ceaseless flux and change; they are
"_always becoming_;" they can not be said to have any "_real being_."
They are not to-day what they were yesterday, and they will never again
be what they are now; consequently all opinions founded on mere
phenomena are equally fluctuating and uncertain. Setting out, therefore,
from the assumption of the fallaciousness of "_opinion_" it examined the
various hypotheses which had been bequeathed by previous schools of
philosophy, or were now offered by contemporaneous speculators, and
showed they were utterly