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childhood； that this hypothesis owes its general wide diffusion
as one of the current beliefs of English…speaking people。 If you
turn to the seventh book of 〃Paradise Lost；〃 you will find there
stated the hypothesis to which I refer； which is briefly this：
That this visible universe of ours came into existence at no
great distance of time from the present； and that the parts of
which it is composed made their appearance； in a certain
definite order； in the space of six natural days； in such a
manner that； on the first of these days； light appeared； that；
on the second； the firmament； or sky； separated the waters
above； from the waters beneath the firmament； that； on the third
day； the waters drew away from the dry land； and upon it a
varied vegetable life； similar to that which now exists； made
its appearance； that the fourth day was signalised by the
apparition of the sun； the stars； the moon； and the planets；
that； on the fifth day； aquatic animals originated within the
waters； that； on the sixth day； the earth gave rise to our four…
footed terrestrial creatures； and to all varieties of
terrestrial animals except birds； which had appeared on the
preceding day； and； finally； that man appeared upon the earth；
and the emergence of the universe from chaos was finished。
Milton tells us； without the least ambiguity； what a spectator
of these marvellous occurrences would have witnessed。 I doubt
not that his poem is familiar to all of you； but I should like
to recall one passage to your minds； in order that I may be
justified in what I have said regarding the perfectly concrete；
definite； picture of the origin of the animal world which Milton
draws。 He says：
〃The sixth； and of creation last； arose
With evening harp and matin； when God said；
'Let the earth bring forth soul living in her kind；
Cattle and creeping things； and beast of the earth。
Each in their kind！' The earth obeyed； and； straight
Opening her fertile womb； teemed at a birth
Innumerous living creatures； perfect forms；
Limbed and full…grown。 Out of the ground uprose；
As from his lair； the wild beast； where he wons
In forest wild； in thicket； brake； or den；
Among the trees in pairs they rose； they walked；
The cattle in the fields and meadows green；
Those rare and solitary； these in flocks
Pasturing at once； and in broad herds upsprung。
The grassy clods now calved； now half appears
The tawny lion； pawing to get free
His hinder partsthen springs； as broke from bonds；
And rampant shakes his brinded mane； the ounce；
The libbard； and the tiger； as the mole
Rising； the crumbled earth above them threw
In hillocks； the swift stag from underground
Bore up his branching head； scarce from his mould
Behemoth； biggest born of earth； upheaved
His vastness； fleeced the flocks and bleating rose
As plants； ambiguous between sea and land；
The river…horse and scaly crocodile。
At once came forth whatever creeps the ground；
Insect or worm。〃
There is no doubt as to the meaning of this statement； nor as to
what a man of Milton's genius expected would have been actually
visible to an eye…witness of this mode of origination of
living things。
The third hypothesis； or the hypothesis of evolution； supposes
that； at any comparatively late period of past time； our
imaginary spectator would meet with a state of things very
similar to that which now obtains； but that the likeness of the
past to the present would gradually become less and less； in
proportion to the remoteness of his period of observation from
the present day； that the existing distribution of mountains and
plains； of rivers and seas； would show itself to be the product
of a slow process of natural change operating upon more and more
widely different antecedent conditions of the mineral frame…work
of the earth； until； at length； in place of that frame…work； he
would behold only a vast nebulous mass； representing the
constituents of the sun and of the planetary bodies。 Preceding
the forms of life which now exist； our observer would see
animals and plants； not identical with them； but like them；
increasing their differences with their antiquity and； at the
same time； becoming simpler and simpler； until； finally； the
world of life would present nothing but that undifferentiated
protoplasmic matter which； so far as our present knowledge goes；
is the common foundation of all vital activity。
The hypothesis of evolution supposes that in all this vast
progression there would be no breach of continuity； no point at
which we could say 〃This is a natural process；〃 and 〃This is not
a natural process；〃 but that the whole might be compared to that
wonderful operation of development which may be seen going on
every day under our eyes； in virtue of which there arises； out
of the semi…fluid comparatively homogeneous substance which we
call an egg； the complicated organisation of one of the higher
animals。 That； in a few words； is what is meant by the
hypothesis of evolution。
I have already suggested that； in dealing with these three
hypotheses； in endeavouring to form a judgment as to which of
them is the more worthy of belief； or whether none is worthy of
beliefin which case our condition of mind should be that
suspension of judgment which is so difficult to all but trained
intellectswe should be indifferent to all a priori
considerations。 The question is a question of historical fact。
The universe has come into existence somehow or other； and the
problem is； whether it came into existence in one fashion； or
whether it came into existence in another； and； as an essential
preliminary to further discussion； permit me to say two or three
words as to the nature and the kinds of historical evidence。
The evidence as to the occurrence of any event in past time may
be ranged under two heads which； for convenience' sake； I will
speak of as testimonial evidence and as circumstantial evidence。
By testimonial evidence I mean human testimony； and by
circumstantial evidence I mean evidence which is not human
testimony。 Let me illustrate by a familiar example what I
understand by these two kinds of evidence； and what is to be
said respecting their value。
Suppose that a man tells you that he saw a person strike another
and kill him； that is testimonial evidence of the fact of
murder。 But it is possible to have circumstantial evidence of
the fact of murder； that is to say； you may find a man dying
with a wound upon his head having exactly the form and character
of the wound which is made by an axe； and； with due care in
taking surrounding circumstances into account； you may conclude
with the utmost certainty that the man has been murdered；
that his death is the consequence of a blow inflicted by another
man with that implement。 We are very much in the habit of
considering circumstantial evidence as of less value than
testimonial evidence； and it may be that； where the
circumstances are not perfectly clear and intelligible； it is a
dangerous and unsafe kind of evidence； but it must not be
forgotten that； in many cases； circumstantial is quite as
conclusive as testimonial evidence； and that； not unfrequently；
it is a great deal weightier than testimonial evidence。
For example； take the case to which I referred just now。
The circumstantial evidence may be better and more convincing
than the testimonial evidence； for it may be impossible； under
the conditions that I have defined； to suppose that the man met
his death from any cause but the violent blow of an axe wielded
by another man。 The circumstantial evidence in favour of a
murder having been committed； in that case； is as complete and
as convincing as evidence can be。 It is evidence which is open
to no doubt and to no falsification。 But the testimony of a
witness is open to multitudinous doubts。 He may have been
mistaken。 He may have been actuated by malice。 It has constantly
happened that even an accurate man has declared that a thing has
happened in this； that； or the other way； when a careful
analysis of the circumstantial evidence has shown that it did
not happen in that way； but in some other way。
We may now consider the evidence in favour of or against the
three hypotheses。 Let me first direct your attention to what is
to be said about the hypothesis of the eternity of the state of
things in which we now live。 What will first strike you is； that
it is a hypothesis which； whether true or false； is not capable
of verification by any evidence。 For； in order to obtain either
circumstantial or testimonial evidence sufficient to prove the
eternity of duration of the present state of nature； you must
have an eternity of witnesses or an infinity of circumstances；
and neither of these is attainable。 It is utterly impossible
that such evidence should be carried beyond a certain point of
time； and all that could be said； at most； would be； that s