A candle loses nothing by lighting another candle.

Are the humanistic and scientific approaches different? Scientists can calculate the torsion of a skyscraper at the wing-beat of a bird, or 155 motions of the Moon and 500 smaller ones in addition. They move in academic garb and sing logarithms. They say, “The sky is ours”, like priests in charge of heaven. We poor humanists cannot even think clearly, or write a sentence without a blunder, commoners of “common sense”. We never take a step without stumbling; they move solemnly, ever unerringly, never a step back, and carry bell, book, and candle.

Chemistry teaches us to regard under one aspect, as various types of combustion or oxidation, the burning of a candle, the rusting of metals, the physiological process of respiration, and the explosion of gunpowder. In each process there is the one common fact that oxygen enters into new chemical combinations. Similarly to the physicist, the fall of the traditional apple of Newton, the revolution of the earth and planets round the sun, the apparitions of comets, and the ebb and flow of the tides are all phases of the universal law of gravitation. A race ignorant of the nature of combustion or of the law of gravitation, and ignorant of the need of such generalisations, could not be considered to have advanced far along the paths of scientific discovery.

Curiosity is the wick in the candle of learning.

Edna St Vincent Millay said:
My candle burns at both ends;
It will not last the night;
But, ah, my foes, and oh, my friends –
It gives a lovely light.
So it is with Gaia. The first aeons of her life were bacterial, and only in her equivalent of late middle age did the first meta-fauna and meta-zoa appear. Not until her eighties did the first intelligent animal appear on the planet. Whatever our faults, we surely have enlightened Gaia’s seniority by letting her see herself from space as a whole planet while she was still beautiful.

How science dwindles, and how volumes swell,
How commentators each dark passage shun,
And hold their farthing candle to the sun!

I ... express a wish that you may, in your generation, be fit to compare to a candle; that you may, like it, shine as lights to those about you; that, in all your actions, you may justify the beauty of the taper by making your deeds honourable and effectual in the discharge of your duty to your fellow-men.
[Concluding remarks for the final lecture (Christmas 1860-61) for children at the Royal Institution. These six lectures were the first series in the tradition of Christmas lectures continued to the present day.]

I always love geology. In winter, particularly, it is pleasant to listen to theories about the great mountains one visited in the summer; or about the Flood or volcanoes; about great catastrophes or about blisters; above all about fossils … Everywhere there are hypotheses, but nowhere truths; many workmen, but no experts; priests, but no God. In these circumstances each man can bring his hypothesis like a candle to a burning altar, and on seeing his candle lit declare ‘Smoke for smoke, sir, mine is better than yours’. It is precisely for this reason that I love geology.

I am here to support the assertion that light of every kind is itself an electrical phenomenon—the light of the sun, the light of a candle, the light of a glowworm.

I purpose, in return for the honour you do us by coming to see what are our proceedings here, to bring before you, in the course of these lectures, the Chemical History of a Candle. I have taken this subject on a former occasion; and were it left to my own will, I should prefer to repeat it almost every year—so abundant is the interest that attaches itself to the subject, so wonderful are the varieties of outlet which it offers into the various departments of philosophy. There is not a law under which any part of this universe is governed which does not come into play, and is touched upon in these phenomena. There is no better, there is no more open door by which you can enter the study of natural philosophy, than by considering the physical phenomena of a candle.

I say it is impossible that so sensible a people [citizens of Paris], under such circumstances, should have lived so long by the smoky, unwholesome, and enormously expensive light of candles, if they had really known that they might have had as much pure light of the sun for nothing.
[Describing the energy-saving benefit of adopting daylight saving time. (1784)]

I took a glass retort, capable of containing eight ounces of water, and distilled fuming spirit of nitre according to the usual method. In the beginning the acid passed over red, then it became colourless, and lastly again all red: no sooner did this happen, than I took away the receiver; and tied to the mouth of the retort a bladder emptied of air, which I had moistened in its inside with milk of lime lac calcis, (i.e. lime-water, containing more quicklime than water can dissolve) to prevent its being corroded by the acid. Then I continued the distillation, and the bladder gradually expanded. Here-upon I left every thing to cool, tied up the bladder, and took it off from the mouth of the retort.— I filled a ten-ounce glass with this air and put a small burning candle into it; when immediately the candle burnt with a large flame, of so vivid a light that it dazzled the eyes. I mixed one part of this air with three parts of air, wherein fire would not burn; and this mixture afforded air, in every respect familiar to the common sort. Since this air is absolutely necessary for the generation of fire, and makes about one-third of our common air, I shall henceforth, for shortness sake call it empyreal air, [literally fire-air] the air which is unserviceable for the fiery phenomenon, and which makes abut two-thirds of common air, I shall for the future call foul air [literally corrupted air].

If a small animal and a lighted candle be placed in a closed flask, so that no air can enter, in a short time the candle will go out, nor will the animal long survive. ... The animal is not suffocated by the smoke of the candle. ... The reason why the animal can live some time after the candle has gone out seems to be that the flame needs a continuous rapid and full supply of nitro-aereal particles. ... For animals, a less aereal spirit is sufficient. ... The movements of the lungs help not a little towards sucking in aereal particles which may remain in said flask and towards transferring them to the blood of the animal.
Remarking (a hundred years before Priestley identified oxygen) that a component of the air is taken into the blood.

If Thomas Edison had gone to business school, we would all be reading by larger candles.

If thou hast knowledge, let others light their candle at thine.

It is better to light one candle than to curse the darkness.

Life is no brief candle to me. It is a sort of splendid torch which I have got a hold of for the moment, and I want to make it burn as brightly as possible before handing it on to future generations.

My experiences with science led me to God. They challenge science to prove the existence of God. But must we really light a candle to see the sun?

Now I must take you to a very interesting part of our subject—to the relation between the combustion of a candle and that living kind of combustion which goes on within us. In every one of us there is a living process of combustion going on very similar to that of a candle, and I must try to make that plain to you. For it is not merely true in a poetical sense—the relation of the life of man to a taper; and if you will follow, I think I can make this clear.

Oh Diamond! Diamond! thou little knowest the mischief done! [Apocryphal]

On the 1st of August, 1774, I endeavoured to extract air from mercurius calcinates per se [mercury oxide]; and I presently found that, by means of this lens, air was expelled from it very readily. … I admitted water to it [the extracted air], and found that it was not imbibed by it. But what surprized me more than I can well express, was, that a candle burned in this air with a remarkably vigorous flame… I was utterly at a loss how to account for it.

The days of my youth extend backward to the dark ages, for I was born when the rush-light, the tallow-dip or the solitary blaze of the hearth were common means of indoor lighting, and an infrequent glass bowl, raised 8 or 10 feet on a wooden post, and containing a cup full of evil-smelling train-oil with a crude cotton wick stuck in it, served to make the darkness visible out of doors. In the chambers of the great, the wax candle or, exceptionally, a multiplicity of them, relieved the gloom on state occasions, but as a rule, the common people, wanting the inducement of indoor brightness such as we enjoy, went to bed soon after sunset.

The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. He who knows it not and can no longer wonder, no longer feel amazement, is as good as dead, a snuffed-out candle. It was the experience of mystery–even if mixed with fear–that engendered religion. A knowledge of the existence of something we cannot penetrate, of the manifestations of the profoundest reason and the most radiant beauty, which are only accessible to our reason in their most elementary forms–it is this knowledge and this emotion that constitute the truly religious attitude; in this sense, and in this alone, I am a deeply religious man.

The larger our great cities grow, the more irresistible becomes the attraction which they exert on the children of the country, who are fascinated by them, as the birds are fascinated by the lighthouse or the moths by the candle.

The Reader may here observe the Force of Numbers, which can be successfully applied, even to those things, which one would imagine are subject to no Rules. There are very few things which we know, which are not capable of being reduc’d to a Mathematical Reasoning, and when they cannot, it’s a sign our Knowledge of them is very small and confus’d; and where a mathematical reasoning can be had, it’s as great folly to make use of any other, as to grope for a thing in the dark when you have a Candle standing by you.

The skein of human continuity must often become this tenuous across the centuries (hanging by a thread, in the old cliché), but the circle remains unbroken if I can touch the ink of Lavoisier’s own name, written by his own hand. A candle of light, nurtured by the oxygen of his greatest discovery, never burns out if we cherish the intellectual heritage of such unfractured filiation across the ages. We may also wish to contemplate the genuine physical thread of nucleic acid that ties each of us to the common bacterial ancestor of all living creatures, born on Lavoisier’s ancienne terre more than 3.5 billion years ago—and never since disrupted, not for one moment, not for one generation. Such a legacy must be worth preserving from all the guillotines of our folly.

The strength of all sciences is, as the strength of the old man’s faggot, in the band. For the harmony of a science, supporting each part the other, is and ought to be the true and brief confutation and suppression of all the smaller sort of objections; but, on the other side, if you take out every axiom, as the sticks of the faggot, one by one, you may quarrel with them and bend them and break them at your pleasure: so that, as was said of Seneca, Verborum minutiis rerum frangit pondera [that he broke up the weight and mass of the matter by verbal points and niceties], so a man may truly say of the schoolmen, Quaestionum minutiis scientiarum frangunt soliditatem [they broke up the solidarity and coherency of the sciences by the minuteness and nicety of their questions]. For were it not better for a man in fair room to set up one great light, or branching candlestick of lights, than to go about with a small watch-candle into every corner?

We must view young people not as empty bottles to be filled, but as candles to be lit.

We speak of it [astrology] as an extinct science; yet let but an eclipse of the sun happen, or a comet visit the evening sky, and in a moment we all believe in astrology. In vain do you tell the gazers on such spectacles that a solar eclipse is only the moon acting for the time as a candle-extinguisher to the sun, and give them bits of smoked glass to look through, and draw diagrams on the blackboard to explain it all. They listen composedly, and seem convinced, but in their secret hearts they are saying—“What though you can see it through a glass darkly, and draw it on a blackboard, does that show that it has no moral significance? You can draw a gallows or a guillotine, or write the Ten Commandments on a blackboard, but does that deprive them of meaning?” And so with the comet. No man will believe that the splendid stranger is hurrying through the sky solely on a momentous errand of his own. No! he is plainly signalling, with that flashing sword of his, something of importance to men,—something at all events that, if we could make it out, would be found of huge concern to us.

What is it, that makes a man willing to sit up on top of an enormous Roman candle, such as a Redstone, Atlas, Titan or Saturn rocket, and wait for someone to light the fuse? (1979)

When Thomas Edison worked late into the night on the electric light, he had to do it by gas lamp or candle. I’m sure it made the work seem that much more urgent.

You will be astonished when I tell you what this curious play of carbon amounts to. A candle will burn some four, five, six, or seven hours. What, then, must be the daily amount of carbon going up into the air in the way of carbonic acid! ... Then what becomes of it? Wonderful is it to find that the change produced by respiration ... is the very life and support of plants and vegetables that grow upon the surface of the earth.