An introduction to mathematics, by A. N. Whitehead.

GENERALIZATIONS OF NUMBERS 85
operations or steps. These "signed" numbers are also particular cases of what have
been called vectors (from the Latin veho, I
draw or carry). For we may think of a
particle as carried from O to A, or from A
to B.
In suggesting a few pages ago that the
practical man would object to the subtlety
involved by the introduction of the positive
and negative numbers, we were libelling that
excellent individual. For in truth we are on
the scene of one of his greatest triumphs. If
the truth must be confessed, it was the practical man himself who first employed the actual
symbols + and -. Their origin is not very
certain, but it seems most probable that they
arose from the marks chalked on chests of
goods in German warehouses, to denote excess
or defect from some standard weight. The
earliest notice of them occurs in a book published at Leipzig, in A.D. 1489. They seem
first to have been employed in mathematics
by a German mathematician, Stifel, in a book
published at Nuremburg in 1544 A.D. But
then it is only recently that the Germans
have come to be looked on as emphatically
a practical nation. There is an old epigram
which assigns the empire of the sea to the
English, of the land to the French, and of the
clouds to the Germans. Surely it was from
the clouds that the Germans fetched + and