and changes of
position of the various atoms, whose very existence is incapable of
proof. Away, then, with chemistry from our schools! The chemist must
only describe the properties of the different elements and those
combinations which can be put before the pupil as ascertained facts
founded in experiment, "the highest means of proof." Everything that
goes beyond this is mischievous, particularly every suggestion as to
the essence and chemical constituents of bodies; matters as to which,
in the nature of things, we can only form uncertain hypotheses. For as
all chemistry, viewed as a system of doctrine, rests solely on such
hypotheses, it may be indeed a subject of investigation but not of
teaching.

Having thus convinced ourselves that chemistry as well as physics,
those "exact sciences," those "mechanical" bases of all other
sciences, rest on mere unproved hypotheses, and so must not be taught,
we may make short work of the other faculties. For they collectively
are more or less historical sciences and dispense wholly or in part
with even those half-exact, fundamental principles on which physics
and chemistry are based. In the first place, there is that grand,
historical, natural science, geology; the great doctrine of the
structure and composition, the origin and development of our globe.
According to Virchow this too must be limited to the description of
ascertained facts, such as the structure of mountain masses, the
character of the fossils they contain, the formation of crystals, and
so forth. But not for the world must anything be taught as to the
evolution of this globe; for this rests from beginning to end on
unproved hypotheses. For even to the present day the Plutonic and
Neptunic theories are disputing the field, and to this day we know not
as to many of the most important rocks, whether they originated by the
agency of fire or of water. The new and remarkable discoveries of the
great Challenger-expedition threaten to subvert a great many
geological notions which had long been regarded as certain. Then
again, as to fossils. Who can prove with any certainty that these
petrifactions are in truth the fossilised remains of extinct
organisms? They may be--as many distinguished naturalists of even the
last century maintained--marvellous sports of nature, mysterious
"Lusus naturae," or mere rough, inorganic models of the labouring
Creator into which He subsequently "breathed the breath of life;" or
perhaps "ston