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

CHAPTER VII
IMAGINARY NUMBERS
IF the mathematical ideas dealt with in the
last chapter have been a popular success,
those of the present chapter have excited
almost as much general attention. But their
success has been of a different character, it
has been what the French term a succès de
scandale. Not only the practical man, but
also men of letters and philosophers have
expressed their bewilderment at the devotion of mathematicians to mysterious entities
which by their very name are confessed to be
imaginary. At this point it may be useful
to observe that a certain type of minor intellect is always worrying itself and others by
discussion as to the applicability of technical
terms. Are the incommensurable numbers
properly called numbers? Are the positive
and negative numbers really numbers? Are
the imaginary numbers imaginary, and are
they numbers?-are types of such futile
questions. Now, it cannot be too clearly
understood that, in science, technical terms
are names arbitrarily assigned, like Christian
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