Every teacher certainly should know something of non-euclidean geometry. Thus, it forms one of the few parts of mathematics which, at least in scattered catch-words, is talked about in wide circles, so that any teacher may be asked about it at any moment. … Imagine a teacher of physics who is unable to say anything about Röntgen rays, or about radium. A teacher of mathematics who could give no answer to questions about non-euclidean geometry would not make a better impression.
On the other hand, I should like to advise emphatically against bringing non-euclidean into regular school instruction (i.e., beyond occasional suggestions, upon inquiry by interested pupils), as enthusiasts are always recommending. Let us be satisfied if the preceding advice is followed and if the pupils learn to really understand euclidean geometry. After all, it is in order for the teacher to know a little more than the average pupil.

At the bidding of a Peter the Hermit many millions of men swarmed to the East; the words of an hallucinated person … have created the force necessary to triumph over the Graeco-Roman world; an obscure monk like Luther set Europe ablaze and bathed in blood. The voice of a Galileo or a Newton will never have the least echo among the masses. The inventors of genius transform a civilization. The fanatics and the hallucinated create history.

How peacefully he sleep!
Yet may his ever-questing spirit, freed at length
from all the frettings of this little world,
Wander at will among the uncharted stars.
Fairfield his name. Perchance celestial fields
disclosing long sought secrets of the past
Spread 'neath his enraptured gaze
And beasts and men that to his earthly sight
were merely bits of stone shall live again to
gladden those eager eyes.
o let us picture him—enthusiast—scientist—friend—
Seeker of truth and light through all eternity!

I am one of the unpraised, unrewarded millions without whom Statistics would be a bankrupt science. It is we who are born, who marry, who die, in constant ratios. It is we who are born, who marry, who die, in constant ratios; who regularly lose so many umbrellas, post just so many unaddressed letters every year. And there are enthusiasts among us who, without the least thought of their own convenience, allow omnibuses to run over them; or throw themselves month by month, in fixed numbers, from the London bridges.

It was to Hofmeister, working as a young man, an amateur and enthusiast, in the early morning hours of summer months, before business, at Leipzig in the years before 1851, that the vision first appeared of a common type of Life-Cycle, running through Mosses and Ferns to Gymnosperms and Flowering Plants, linking the whole series in one scheme of reproduction and life-history.

Over the last century, physicists have used light quanta, electrons, alpha particles, X-rays, gamma-rays, protons, neutrons and exotic sub-nuclear particles for this purpose [scattering experiments]. Much important information about the target atoms or nuclei or their assemblage has been obtained in this way. In witness of this importance one can point to the unusual concentration of scattering enthusiasts among earlier Nobel Laureate physicists. One could say that physicists just love to perform or interpret scattering experiments.

Society is becoming increasingly aware of the power of science to bring weal or woe to mankind. But now when it is seen that the same science that brings prosperity and comfort may lead to depression and discomfort, men are beginning to look with mixed feelings at this monster which society may exalt or persecute, but cannot view with indifference. Perhaps my topic today should have read “Ought Scientists to be Burnt at the Stake?” I shall not attempt to decide this question, but only to present in a cursory way some of the pros and cons … But if scientists are to be destroyed, let them not alone by the victims; every creative thought must be extirpated. A philosopher’s epigram may kindle a world war. So scientist, inventor, artist, poet and every sort of troublous enthusiast must together be brought before the bar of the new inquisition

That ability to impart knowledge … what does it consist of? … a deep belief in the interest and importance of the thing taught, a concern about it amounting to a sort of passion. A man who knows a subject thoroughly, a man so soaked in it that he eats it, sleeps it and dreams it—this man can always teach it with success, no matter how little he knows of technical pedagogy. That is because there is enthusiasm in him, and because enthusiasm is almost as contagious as fear or the barber’s itch. An enthusiast is willing to go to any trouble to impart the glad news bubbling within him. He thinks that it is important and valuable for to know; given the slightest glow of interest in a pupil to start with, he will fan that glow to a flame. No hollow formalism cripples him and slows him down. He drags his best pupils along as fast as they can go, and he is so full of the thing that he never tires of expounding its elements to the dullest.
This passion, so unordered and yet so potent, explains the capacity for teaching that one frequently observes in scientific men of high attainments in their specialties—for example, Huxley, Ostwald, Karl Ludwig, Virchow, Billroth, Jowett, William G. Sumner, Halsted and Osler—men who knew nothing whatever about the so-called science of pedagogy, and would have derided its alleged principles if they had heard them stated.

The real mathematician is an enthusiast per se. Without enthusiasm no mathematics.