ng. If an antiquary, desirous of discovering the date of the
catastrophe, should first arrive at a city where several Greek temples
were lying in ruins and half engulphed in the earth, while many Gothic
edifices were standing uninjured, could he determine on these data the
era of the shock? Could he even exclude any one of the three periods,
and decide that it must have happened during one of the other two?
Certainly not. He could merely affirm that it happened at some period
after the introduction of the Greek style, and before the Gothic had
fallen into disuse. Should he pretend to define the date of the
convulsion with greater precision, and decide that the earthquake must
have occurred after the Greek and before the Gothic period, that is to
say, when the Roman style was in use, the fallacy in his reasoning would
be too palpable to escape detection for a moment.

Yet such is the nature of the erroneous induction which I am now
exposing. For as, in the example above proposed, the erection of a
particular edifice is perfectly distinct from the period of architecture
in which it may have been raised, so is the deposition of chalk, or any
other set of strata, from the geological epochs characterized by certain
fossils to which they may belong.

It is almost superfluous to enter into any farther analysis of the
theory of parallelism, because the whole force of the argument depends
on the accuracy of the data by which the contemporaneous or
non-contemporaneous date of the elevation of two independent chains can
be demonstrated. In every case, this evidence, as stated by M. de
Beaumont, is equivocal, because he has not included in the possible
interval of time between the depositions of the deranged and the
horizontal formations, part of the periods to which each of those
classes of formations are referable. Even if all the geological facts,
therefore, adduced by the author were true and unquestionable, yet the
conclusion that certain chains were or were not simultaneously upraised
is by no means a legitimate consequence.

In the third volume of my first edition of the Principles, which
appeared in April, 1833, I controverted the views of M. de Beaumont,
then just published, in the same terms as I have now restated them. At
that time I took for granted that the chronological date of the newest
rocks entering into the disturbed series of the Pyrenees had been
correctly ascertained. It now appears, however, that some of th