"great" university of
Berlin nothing may be taught, as Virchow insists, but what is
objectively ascertained, absolutely sure; that is to say, nothing that
rises above individual, indubitable, and intelligible facts; not an
idea, not a conception, not a theory, in fact not any real science;
mathematics, at most, excepted. It is our conviction that Jena will
continue to be an independent city of refuge for free science and free
teaching as long as it remains under the faithful nurture and liberal
protection of the princely house of Sax Weimar, that enlightened race
which is linked with the history of German intellect through the
matchless traditions of its glorious past. What the Wartburg was to
Martin Luther, what Weimar has been to the foremost heroes of German
literature, what Jena herself has been during three hundred years to a
vast number of illustrious investigators, that will the tried and
tested Jena of to-day undoubtedly continue to be to the modern
doctrine of evolution, as to every other doctrine which asks free
development; a strong-hold of free thought, free investigation, and
free doctrine.

ERNST HAECKEL.

JENA, _June 24th_, 1878.

FOOTNOTES:

[6] Kosmos, Vol. II. p. 172.

[7] Of the German.

[8]

"Wer die Wahrheit kennet und saget sie frei,
Der kommt in Berlin auf die Stadt-Vogtei."

[9]

"Wer die Wahrheit kennet und saget sie nicht
Der ist fuer wahr ein erbaermlicher Wicht."

CONTENTS.

PAGE

PREFATORY NOTE v

PREFACE xxi

CHAP.

I. DEVELOPMENT AND CREATION 1

II. CERTAIN PROOFS OF THE DOCTRINE OF DESCENT 10

III. THE SKULL THEORY AND THE APE THEORY 29

IV. THE CELL-SOUL AND CELLULAR PSYCHOLOGY 46

V. THE GENETIC AND DOGMATIC METHODS OF TEACHING 61

VI. THE DOCTRINE OF DESCENT AND SOCIAL DEMOCRACY 88

VII. IGNORABIMUS ET RESTRINGAMUR 99

FREEDOM IN SCIENCE AND TEACHING.

CHAPTER I.

DEVELOPMENT AND CREATION.

Nothing is more helpful for the understanding of scientific
controversies, or for the clearing of confused conceptions, than a
contrasted statement, as defined and clear as possible, of the
simplest leading propositions of the contending doctrines. He