##### Lichtenberg, Georg Christoph (1742 - 1799)

In mathematical analysis we call x the undetermined part of line a: the rest we don't call y, as we do in common life, but a-x. Hence mathematical language has great advantages over the common language.

##### Lichtenberg, Georg Christoph (1742 - 1799)

The great trick of regarding small departures from the truth as the truth itself -- on which is founded the entire integral calculus -- is also the basis of our witty speculations, where the whole thing would often collapse if we considered the departures with philosophical rigour.

##### Lichtenberg, Georg Christoph (1742-1799)

All mathematical
laws which we find
in Nature are always
suspect to me, in
spite of their
beauty. They give me
no pleasure. They
are merely
auxiliaries. At
close range it is
all not true.

In J P Stern,
*Lichtenberg,*
1959.

##### Leybourn, William (1626-1700)

But leaving those of the Body, I shall proceed to such Recreation as adorn the Mind; of which those of the Mathematicks are inferior to none.

Pleasure with Profit, 1694.

##### Leibniz, Gottfried Wilhelm (1646-1716)

The soul is the
mirror of an
indestructible
universe.

##### Leibniz, Gottfried Wilhelm (1646-1716)

Although the whole
of this life were
said to be nothing
but a dream and the
physical world
nothing but a
phantasm, I should
call this dream or
phantasm real
enough, if, using
reason well, we were
never deceived by
it.

In J. R. Newman
(ed.), The World of
Mathematics, New
York: Simon and
Schuster, 1956.

##### Leibniz, Gottfried Wilhelm (1646-1716)

The art of
discovering the
causes of phenomena,
or true hypothesis,
is like the art of
decyphering, in
which an ingenious
conjecture greatly
shortens the road.

New Essays
Concerning Human
Understanding, IV,
XII.

##### Leibniz, Gottfried Wilhelm (1646-1716)

In symbols one
observes an
advantage in
discovery which is
greatest when they
express the exact
nature of a thing
briefly and, as it
were, picture it;
then indeed the
labor of thought is
wonderfully
diminished.

In G. Simmons,
Calculus Gems, New
York: McGraw Hill
Inc., 1992.

##### Leibniz, Gottfried Wilhelm (1646-1716)

He who understands
Archimedes and
Apollonius will
admire less the
achievements of the
foremost men of
later times.

In G. Simmons,
Calculus Gems, New
York: McGraw Hill
Inc., 1992.

##### Leibniz, Gottfried Wilhelm (1646-1716)

The imaginary number
is a fine and
wonderful recourse
of the divine
spirit, almost an
amphibian between
being and not being.