Front Page Titles (by Subject) METAPHYSICS. - The Works of Voltaire, Vol. VI (Philosophical Dictionary Part 4)
The Online Library of Liberty
A project of Liberty Fund, Inc.
METAPHYSICS. - Voltaire, The Works of Voltaire, Vol. VI (Philosophical Dictionary Part 4) 
The Works of Voltaire. A Contemporary Version. A Critique and Biography by John Morley, notes by Tobias Smollett, trans. William F. Fleming (New York: E.R. DuMont, 1901). In 21 vols. Vol. VI.
About Liberty Fund:
The text is in the public domain.
Fair use statement:
“Trans naturam,”—beyond nature. But what is that which is beyond nature? By nature, it is to be presumed, is meant matter, and metaphysics relates to that which is not matter.
For example: to your reasoning, which is neither long, nor wide, nor high, nor solid, nor pointed; your soul, to yourself unknown, which produces your reasoning.
Spirits, which the world has always talked of, and to which mankind appropriated, for a long period, a body so attenuated and shadowy, that it could scarcely be called body; but from which, at length, they have removed every shadow of body, without knowing what it was that was left.
The manner in which these spirits perceive, without any embarrassment, from the five senses; in which they think, without a head; and in which they communicate their thoughts, without words and signs.
Finally, God, whom we know by His works, but whom our pride impels us to define; God, whose power we feel to be immense; God, between whom and ourselves exists the abyss of infinity, and yet whose nature we dare to attempt to fathom.
These are the objects of metaphysics. We might further add to these the principles of pure mathematics, points without extension, lines without width, superficies without thickness, units infinitely divisible, etc.
Bayle himself considered these objects as those which were denominated “entia rationis,” beings of reason; they are, however, in fact, only material things considered in their masses, their superficies, their simple lengths and breadths, and the extremities of these simple lengths and breadths. All measures are precise and demonstrated. Metaphysics has nothing to do with geometry.
Thus a man may be a metaphysician without being a geometrician. Metaphysics is more entertaining; it constitutes often the romance of the mind. In geometry, on the contrary, we must calculate and measure; this is a perpetual trouble, and most minds had rather dream pleasantly than fatigue themselves with hard work.