o this Fallacy. The following dogmas express the different forms
of this error:--

1. [Greek: a]. _Things which we cannot help thinking of together must
coexist_; thus Descartes held that, because existence is involved
(though really only by the thinker himself) in the idea of a geometrical
figure, a thing like the idea must exist. [Greek: b]. _Whatever is
inconceivable is false._ The latter proposition has been defended by
drawing a distinction between the principle, and its possibly wrong
application to facts, e.g. to Antipodes; but how can we ever know that
it has been rightly applied? Coleridge, again, has distinguished between
the unimaginable, which he thinks may possibly be true, and the
inconceivable, which he thinks cannot be; but Antipodes were imaginable
at the same period when they were inconceivable. In fact, as even to
Newton it seemed inconceivable, that a thing should act where it is not
(e.g. that the sun should act upon the earth without the medium of an
ether), simply because his mind was not familiar with the idea, so it
_may_ be with _our_ incapability (if not, indeed, resulting merely from
our limited faculties) of _conceiving_, e.g. that matter cannot think;
that space is infinite; that _ex nihilo nihil fit_. Leibnitz's tenet
that all _natural_ phenomena must be explicable _a priori_, and the
further assumption by some that Nature always acts by the simplest, i.e.
by the most easily conceivable means (and that, therefore, e.g. the
heavenly bodies have a circular movement), exhibit vividly this Fallacy
of Simple Inspection.

2. _Whatever can be thought of apart, or has a separate name, exists
apart as a separate entity_, e.g. Nature, Time, qualities, as e.g.
Whiteness, and, worst of all, the Substantiae Secundae. Mysticism is this
habit of ascribing objective existence to the subjective creations of
the mind, and reasoning from them to the things themselves.

3. _A fact must follow a certain law, because we see no reason for its
deviating from it in one way rather than in another._ This, which is the
same as the Principle of the Sufficient Reason, has been used to prove
the Law of Inertia (the very point to be proved, viz. that only external
force can be a sufficient reason for motion _in a particular direction_,
being assumed), and also the First Law of Motion, the argument being, in
the latter case, that a moving body, if it do _not_ continue of itself
to move uniformly in a straight line, must