This principle has always been far from finding universal acceptance.  One of his theological opponents went so far as to affirm that a doctrine may be not only held, but dogmatically insisted on, by a teacher who is, all the time, fully aware that science may ultimately prove it to be quite untenable.

His own course went to the opposite extreme.  In teaching, where it was possible to let the facts speak for themselves, he did not further urge their bearing upon wider problems.  He preferred to warn beginners against drawing superficial inferences in favour of his own general theories, from facts the real meaning of which was not immediately apparent.  Father Hahn (S.J.), who studied under him in 1876, writes:—­

One day when I was talking to him, our conversation turned upon evolution.  “There is one thing about you I cannot understand,” I said, “and I should like a word in explanation.  For several months now I have been attending your course, and I have never heard you mention evolution, while in your public lectures everywhere you openly proclaim yourself an evolutionist.” ("Revue des Questions Scientifiques” (Brussels), for October 1895.)

Now it would be impossible to imagine a better opportunity for insisting on evolution than his lectures on comparative anatomy, when animals are set side by side in respect of the gradual development of functions.  But Huxley was so reserved on this subject in his lectures that, speaking one day of a species forming a transition between two others, he immediately added:—­]

“When I speak of transition I do not in the least mean to say that one species turned into a second to develop thereafter into a third.  What I mean is, that the characters of the second are intermediate between those of the two others.  It is as if I were to say that such a Cathedral, Canterbury, for example, is a transition between York Minster and Westminster Abbey.  No one would imagine, on hearing the word transition, that a transmutation of these buildings actually took place from one into other.” [(Doubtless in connection with the familiar warning that intermediate types are not necessarily links in the direct line of descent.)

But to return to his reply:—­]

“Here in my teaching lectures [he said to me] I have time to put the facts fully before a trained audience.  In my public lectures I am obliged to pass rapidly over the facts, and I put forward my personal convictions.  And it is for this that people come to hear me.”

[As to the question whether children should be brought up in entire disregard to the beliefs rejected by himself, but still current among the mass of his fellow-countrymen, he was of opinion that they ought to know] “the mythology of their time and country,” [otherwise one would at the best tend to make young prigs of them; but as they grew up their questions should be answered frankly. (The wording of a paragraph in Professor Mivart’s “Reminiscences” ("Nineteenth Century”, December 1897, P. 993), tends, I think, to leave a wrong impression on this point.)