--_ratio
pertinens_ is a pertinent reason, that is, a reason _pertaining_ to the
cause in question, and a _ratio impertinens_, an impertinent reason, is
an argument _not pertaining_ to the subject.[44] _Impertinent_ then
originally meant neither absurdity nor rude intrusion, as it does in our
present popular sense. The learned Arnauld having characterised a reply
of one of his adversaries by the epithet _impertinent_, when blamed for
the freedom of his language, explained his meaning by giving this
history of the word, which applies to our own language. Thus also with
us the word _indifferent_ has entirely changed: an historian, whose work
was _indifferently_ written, would formerly have claimed our attention.
In the Liturgy it is prayed that "magistrates may _indifferently_
minister justice." _Indifferently_ originally meant _impartially_. The
word _extravagant_, in its primitive signification, only signified to
digress from the subject. The Decretals, or those letters from the popes
deciding on points of ecclesiastical discipline, were at length
incorporated with the canon law, and were called _extravagant_ by
_wandering out_ of the body of the canon law, being confusedly dispersed
through that collection. When Luther had the Decretals publicly burnt at
Wittemberg, the insult was designed for the pope, rather than as a
condemnation of the canon law itself. Suppose, in the present case, two
persons of opposite opinions. The catholic, who had said that the
decretals were _extravagant_, might not have intended to depreciate
them, or make any concession to the Lutheran. What confusion of words
has the _common sense_ of the Scotch metaphysicians introduced into
philosophy! There are no words, perhaps, in the language which may be so
differently interpreted; and Professor Dugald Stewart has collected, in
a curious note in the second volume of his "Philosophy of the Human
Mind," a singular variety of its opposite significations. The Latin
phrase, _sensus communis_, may, in various passages of Cicero, be
translated by our phrase _common sense_; but, on other occasions, it
means something different; the _sensus communis_ of the schoolmen is
quite another thing, and is synonymous with _conception_, and referred
to the seat of intellect; with Sir John Davies, in his curious
metaphysical poem, _common sense_ is used as _imagination_. It created a
controversy with Beattie and Reid; and Reid, who introduced this vague
ambiguous phra