President, Royal Society

1883 Portrait by John Collier

Appleton ed., Vol VIII frontispiece

Preface VIII (1894)

Discourses: Biological & Geological

Hodeslea, Eastbourne
April, 1894

[v] The contents of the present volume, with three exceptions, are either popular lectures, or addresses delivered to scientific bodies with which I have been officially connected. I am not sure which gave me the more trouble. For I have not been one of those fortunate persons who are able to regard a popular lecture as a mere hors d'œuvre, unworthy of being ranked among the serious efforts of a philosopher; and who keep their fame as scientific hierophants unsullied by attempts–at least of the successful sort–to be understanded of the people.

On the contrary, I found that the task of putting the truths learned in the field, the laboratory and the museum, into language which, without bating a jot of scientific accuracy shall be generally intelligible, taxed such scientific and literary faculty as I possessed to the uttermost; indeed my experience has furnished me with no better corrective of the tendency to scholastic pedantry which besets all those who are absorbed [vi] in pursuits remote from the common ways of men, and become habituated to think and speak in the technical dialect of their own little world, as if there were no other.

If the popular lecture thus, as I believe, finds one moiety of its justification in the self-discipline of the lecturer, it surely finds the other half in its effect on the auditory. For though various sadly comical experiences of the results of my own efforts have led me to entertain a very moderate estimate of the purely intellectual value of lectures; though I venture to doubt if more than one in ten of an average audience carries away an accurate notion of what the speaker has been driving at; yet is that not equally true of the oratory of the hustings, of the House of Commons, and even of the pulpit?

Yet the children of this world are wise in their generation; and both the politician and the priest are justified by results. The living voice has an influence over human action altogether independent of the intellectual worth of that which it utters. Many years ago, I was a guest at a great City dinner. A famous orator, endowed with a voice of rare flexibility and power; a born actor, ranging with ease through every part, from refined comedy to tragic unction, was called upon to reply to a toast. The orator was a very busy man, a charming conversationalist and by no means despised a good dinner; and, I imagine, rose with[vii]out having given a thought to what he was going to say. The rhythmic roll of sound was admirable, the gestures perfect, the earnestness impressive; nothing was lacking save sense and, occasionally grammar. When the speaker sat down the applause was terrific and one of my neighbours was especially enthusiastic. So when he had quieted down, I asked him what the orator had said. And he could not tell me.

That sagacious person, John Wesley, is reported to have replied to some one who questioned the propriety of his adaptation of sacred words to extremely secular airs, that he did not see why the Devil should be left in possession of all the best tunes. And I do not see why science should not turn to account the peculiarities of human nature thus exploited by other agencies: all the more because science, by the nature of its being, cannot desire to stir the passions, or profit by the weaknesses, of human nature. The most zealous of popular lecturers can aim at nothing more than the awakening of a sympathy for abstract truth, in those who do not really follow his arguments; and of a desire to know more and better in the few who do.

At the same time it must be admitted that the popularization of science, whether by lecture or essay, has its drawbacks. Success in this department has its perils for those who succeed. The "people who fail" take their revenge, as we have [viii] recently had occasion to observe, by ignoring all the rest of a man's work and glibly labelling him a mere popularizer. If the falsehood were not too glaring, they would say the same of Faraday and Helmholtz and Kelvin.

On the other hand, of the affliction caused by persons who think that what they have picked up from popular exposition qualifies them for discussing the great problems of science, it may be said, as the Radical toast said of the power of the Crown in bygone days, that it "has increased, is increasing, and ought to be diminished." The oddities of "English as she is spoke" might be abundantly paralleled by those of "Science as she is misunderstood" in the sermon, the novel, and the leading article; and a collection of the grotesque travesties of scientific conceptions, in the shape of essays on such trifles as "the Nature of Life" and the "Origin of All Things," which reach me, from time to time, might well be bound up with them.

The tenth essay in this volume unfortunately brought me, I will not say into collision, but into a position of critical remonstrance with regard to some charges of physical heterodoxy, brought by my distinguished friend Lord Kelvin, against British Geology. As President of the Geological Society of London at that time (1869), I thought I might venture to plead that we were not such heretics as we seemed to be; and that, even if [ix] we were, recantation would not affect the question of evolution.

I am glad to see that Lord Kelvin has just reprinted his reply to my plea,1 and I refer the reader to it. I shall not presume to question anything, that on such ripe consideration, Lord Kelvin has to say upon the physical problems involved. But I may remark that no one can have asserted more strongly than I have done, the necessity of looking to physics and mathematics, for help in regard to the earliest history of the globe. (See pp. 108 and 109 of this volume.)

And I take the opportunity of repeating the opinion, that, whether what we call geological time has the lower limit assigned to it by Lord Kelvin, or the higher assumed by other philosophers; whether the germs of all living things have originated in the globe itself, or whether they have been imported on, or in, meteorites from without, the problem of the origin of those successive Faunæ and Floræ of the earth, the existence of which is fully demonstrated by palæontology remains exactly where it was.

For I think it will be admitted, that the germs brought to us by meteorites, if any, were not ova of elephants, nor of crocodiles; nor cocoa-nuts nor acorns; not even eggs of shell-fish and corals; but only those of the lowest forms of animal and vegetable life. Therefore since it is proved that, [x] from a very remote epoch of geological time, the earth has been peopled by a continual succession of the higher forms of animals and plants, these either must have been created, or they have arisen by evolution. And in respect of certain groups of animals, the well-established facts of palæontology leave no rational doubt that they arose by the latter method.

In the second place, there are no data whatever, which justify the biologist in assigning any, even approximately definite, period of time, either long or short, to the evolution of one species from another by the process of variation and selection. In the ninth of the following essays, I have taken pains to prove that the change of animals has gone on at very different rates in different groups of living beings; that some types have persisted with little change from the palæozoic epoch till now, while others have changed rapidly within the limits of an epoch. In 1862 (see below p. 303, 304) in 1863 (vol. II., p. 461) and again in 1864 (ibid., p. 89–91) I argued, not as a matter of speculation, but, from palæontological facts, the bearing of which I believe, up to that time, had not been shown, that any adequate hypothesis of the causes of evolution must be consistent with progression, stationariness and retrogression, of the same type at different epochs; of different types in the same epoch; and that Darwin's hypothesis fulfilled these conditions.

[xi] According to that hypothesis, two factors are at work, variation and selection. Next to nothing is known of the causes of the former process; nothing whatever of the time required for the production of a certain amount of deviation from the existing type. And, as respects selection, which operates by extinguishing all but a small minority of variations, we have not the slightest means of estimating the rapidity with which it does its work. All that we are justified in saying is that the rate at which it takes place may vary almost indefinitely. If the famous paint-root of Florida, which kills white pigs but not black ones, were abundant and certain in its action, black pigs might be substituted for white in the course of two or three years. If, on the other hand, it was rare and uncertain in action, the white pigs might linger on for centuries.

1 Popular Lectures and Addresses. II. Macmillan and Co., 1894.


I On a Piece of Chalk [1865] 1
II The Problems of the Deep Sea [1873] 37
III On Some of the Results of the Expedition of H.M.S. "Challenger" [1875] 69
IV Yeast [1871] 112
V On the Formation of Coal [1870]
(A Lecture delivered at the Philosophical Institution, Bradford.)
VI On the Border Territory between the Animal and the Vegetable Kingdoms [1876]
(A Friday evening Lecture delivered at the Royal Institution.)
VII A Lobster; or, the Study of Zoology [1861]
(A Lecture delivered at the South Kensington Museum.)
VIII Biogenesis and Abiogenesis [1870]
(The President's Address to the Meeting of the British Association for the dvancement of Science at Liverpool.)
IX Geological Contemporaneity and Persistent Types of Life [1862]
(Address to the Geological Society on behalf of the President by one of the Secretaries.)
X Geological Reform [1869]
(Presidential Address to the Geological Society.)
XI Palæontology and the Doctrine of Evolution [1870]
(Presidential Address to the Geological Society.)


Huxley's Collected Essays.

Volume I, Method and Results
Volume II, Darwiniana
Volume III, Science & Education
Volume IV, Science and Hebrew Tradition
Volume V, Science and Christian Tradition
Volume VI, Hume: With Helps to the Study of Berkeley
Volume VII, Man's Place in Nature
Volume VIII, Discourses: Biological & Geological
Volume IX, Evolution & Ethics and Other Essays



1.   THH Publications
2.   Victorian Commentary
3.   20th Century Commentary

1.   Letter Index
2.   Illustration Index

Gratitude and Permissions

C. Blinderman & D. Joyce
Clark University

§ 1. THH: His Mark
§ 2. Voyage of the Rattlesnake
§ 3. A Sort of Firm
§ 4. Darwin's Bulldog
§ 5. Hidden Bond: Evolution
§ 6. Frankensteinosaurus
§ 7. Bobbing Angels: Human Evolution
§ 8. Matter of Life: Protoplasm
§ 9. Medusa
§ 10. Liberal Education
§ 11. Scientific Education
§ 12. Unity in Diversity
§ 13. Agnosticism
§ 14. New Reformation
§ 15. Verbal Delusions: The Bible
§ 16. Miltonic Hypothesis: Genesis
§ 17. Extremely Wonderful Events: Resurrection and Demons
§ 18. Emancipation: Gender and Race
§ 19. Aryans et al.: Ethnology
§ 20. The Good of Mankind
§ 21.  Jungle Versus Garden