Natural Philosophers

"[M]an, like the heavenly bodies, oscillates between fire and water; and that is... what Herakleitos taught."

"[N]either fire nor water can prevail completely... The whole process depends... on the fact that Surfeit is... Want... [i.e.,] an advance of fire increases the moist exhalation, while an advance of water deprives the fire of the power to cause evaporation. The conflagration... would destroy the opposite tension on which the rise of a new world depends, and... motion would become impossible."

"We know from Philo that Herakleitos supported his theory of the attainment of harmony through strife... There is... agreement between a passage of this kind in the pseudo-Aristotelian treatise... The Kosmos, and the Hippokratean work... [B]oth drew from... Herakleitos... made practically certain by the fact that this agreement extends... to the Letters of Herakleitos, which, though spurious, were... composed by some one who had access to the original work."

"The argument was that men... act just in the same way as Nature, and it is therefore surprising that they do not recognise the laws by which she works."

"The painter produces his harmonious effects by the contrast of colours, the musician by that of high and low notes. "If one were to make all things alike, there would be no delight in them." There are many similar examples in the Hippokratean tract, some... come from Herakleitos; but it is not easy to separate them..."

"[A] number of Herakleitean fragments... form a class by themselves, and are among the most striking... Their common characteristic... they assert... the identity of... things... usually regarded as opposites."

"Herakleitos meant to say, not that day was night or that night was day, but that they were two sides of the same process, namely, the oscillation of the "measures" of fire and water, and... neither would be possible without the other."

"Any explanation... of night will... be an explanation of day, and vice versa; for it will be an account of that which is common... manifests itself now as one and now as the other. ...[B]ecause it has manifested... in the one form... it must next appear in the other... [as] required by the law of compensation or Justice."

"This is only a particular application of the universal principle that the primary fire is one even in its division. It itself is, even in its unity, both surfeit and want, war and peace (fr. 36)."

"[T]he "satiety" which makes fire pass into other forms, which makes it seek "rest in change" (frs. 82, 83), and "hide itself" (fr. 10) in the "hidden attunement" of opposition, is only one side of the process. The other is the "want" which leads it to consume the bright vapour as fuel. The upward path is nothing without the downward (fr. 69). If either were to cease, the other would cease... and the world would disappear; for it takes both to make... stable reality."

"All other utterances of the kind are to be explained in the same way."

"If there were no cold, there would be no heat; for a thing can only grow warm if... it is already cold."

"[T]he same thing applies to the opposition of wet and dry (fr. 39)."

"These... are... the two primary oppositions of Anaximander, and Herakleitos is showing that the war... is really peace, for it is the common element in them (fr. 62) which appears as strife, and that... strife is justice, and not, as Anaximander had taught, an injustice... they commit one against the other, and which must be expiated by a reabsorption of both in their common ground."

"The strife itself is the common ground (fr. 62), and is eternal."

"The most startling of these sayings is that which affirms that good and evil are the same (fr. 57). This does not mean in the least... that good is evil or that evil is good, but... that they are the two inseparable halves of one and the same thing."

"A thing can become good only in so far as it is already evil, and evil only in so far as it is already good... everything depends on the contrast."

"At the upper end, where the two paths meet, we have the pure fire, in which, as there is no separation, there is no relativity."

"[W]hile to man some things are evil and some things are good, all things are good to God (fr.61). ...[B]y God ...Herakleitos meant fire. He also calls it the "one wise," and perhaps said... it "knows all things." ...[H]e meant to say ...in it the opposition and relativity which are universal in the world disappear. ...[T]o this ...frs. 96, 97, and 98 refer."

"Herakleitos speaks of "wisdom" or the "wise" in two senses. ...[H]e said wisdom was "something apart from everything else" (fr. 18), meaning ...the perception of the unity of the many ...[H]e also applies the term to that unity... regarded as the "thought that directs the course of all things." This is synonymous with the pure fire which is not differentiated into two parts, one taking the upward and the other the downward path. That alone has wisdom; the partial things we see have not. We ourselves are only wise in so far as we are fiery (fr. 74)."

"With... reservations, Herakleitos was prepared to call the one Wisdom by the name of Zeus. Such... appears to be the meaning of fr. 65. It is not... to be pictured in the form of a man. In saying this, Herakleitos would only have been repeating... Anaximander and Xenophanes. He agrees further with Xenophanes in holding that this "god"... is one; but his polemic against popular religion was directed... against the rites and ceremonies... [rather] than their mere mythological outgrowth."

"He gives a list (fr. 124) of some of the most characteristic religious figures of his time, and... threatened them with the wrath to come."

"He comments upon the absurdity of praying to images (fr. 126), and... that blood-guiltiness can be washed out by the shedding of blood (fr. 130)."

"He seems also to have said that it was absurd to celebrate the worship of Dionysos by cheerful and licentious ceremonies, while was propitiated by gloomy rites (fr. 127). According to the mystic doctrine itself, the two were really one; and the one Wisdom ought to be worshipped in its integrity."

"The few fragments which deal with theology and religion hardly suggest to us that Herakleitos was in sympathy with the religious revival of the time, and yet we have been asked to consider his system "in the light of the idea of the mysteries.""

"The moral teaching of Herakleitos has sometimes been regarded as an anticipation of the "commonsense" theory of Ethics."

"The "common" upon which Herakleitos insists is... very different from common sense, for which... he had the greatest... contempt (fr. 111). It is... his strongest objection to "the many," that they live each in his own world (fr. 95), as if they had a private wisdom of their own (fr. 92); and public opinion is therefore... opposite of "the common.""

"The Ethics of Herakleitos are to be regarded as a corollary of his anthropological and cosmological views. Their chief requirement... keep our souls dry, and thus assimilate them to the one Wisdom... fire. That is what is... "common," and the greatest fault is to act like men asleep (fr. 94)... by letting our souls grow moist, to cut ourselves off from the fire in the world."

"The wise man would not try to secure good without its correlative evil. He would not seek for rest without exertion, nor expect to enjoy contentment without first suffering discontent. He would not complain that he had to take the bad with the good, but would consistently look at things as a whole."

"Herakleitos prepared the way for the Stoic world-state by comparing "the common" to the laws of a city. And these are... more than a type of the divine law: they are imperfect embodiments of it. They cannot... exhaust it altogether; for in all human affairs there is an element of relativity (fr. 91). "Man is a baby compared to God" (fr. 97). Such as they are, however, the city must fight for them as for its walls; and, if it has the good fortune to possess a citizen with a dry soul, he is worth ten thousand (fr. 113); for in him alone is "the common" embodied."

"Tesla has contributed more to electrical science than any man up to his time."

"Thomson was a mathematical prodigy. At age 16, he mastered ’s ' and wrote and published a defense of it. Fourier’s theory allowed one to determine the distribution of heat in a body on the sole assumption that heat flow is proportional to temperature gradient. The approach was macroscopic, geometrical, and nonhypothetical, and Thomson took to it easily. During his undergraduate years at , he traveled to Paris and met the mathematical savants—in particular, mathematician Joseph Liouville and experimental physicist , who both considered Michael Faraday’s curved lines of force outré. At Liouville’s urging, Thomson produced for the ' a demonstration that the lines of force, whether electric or magnetic, followed from inverse square laws. The relevant mathematics was a near cousin to that for heat flow, but the insight was new and would be seminal in the thinking that led James Clerk Maxwell to electromagnetic field theory."

"If materialism cannot consistently escape the conclusion of a finite state, which William Thomson has traced out for it, then materialism is thereby refuted."

"According to Sir W. Thomson's theory of Vortex Atoms, the substance of which the molecule consists is a uniformly dense plenum, the properties of which are those of a perfect fluid, the molecule itself being nothing but a certain motion impressed on a portion of this fluid, and this motion is shewn, by a theorem due to Helmholtz, to be as indestructible as we believe a portion of matter to be."

"The man of true Physical instincts, endowed with the great faculty of scientific imagination, possessed for example by Lord Kelvin in a very remarkable degree, is for ever imagining models which shall enable him by their working to represent and depict the course of actual physical processes. The possibility and consistency of such models require Mathematical Analysis for their investigation."

"He was one of the few scientists to be knighted, and the only one in the nineteenth century to be raised to the peerage. These honors, however, were not in recognition of his scientific work but his genius as an engineer in solving the major technical problems of laying the first Atlantic cable and his entrepreneurial success as an instrument designer and manufacturer for the new electrical industries and the Navy. With his success with the Atlantic cable Kelvin became a symbol of science to the general public."

"There is nothing new to be discovered in physics now. All that remains is more and more precise measurement."

"The beauty and clearness of the dynamical theory, which asserts heat and light to be modes of motion, is at present obscured by two clouds. I. The first came into existence with the undulatory theory of light, and was dealt with by Fresnel and Dr. Thomas Young; it involved the question, how could the earth move through an elastic solid, such as essentially is the luminiferous ether? II. The second is the Maxwell–Boltzmann doctrine regarding the partition of energy."

"If the water flow down by a gradual natural channel, its potential energy is gradually converted into heat by fluid friction, according to an admirable discovery made by Mr Joule of Manchester above twelve years ago, which has led to the greatest reform that physical science has experienced since the days of Newton. From that discovery, it may be concluded with certainty that heat is not matter, but some kind of motion among the particles of matter; a conclusion established, it is true, by Sir Humphrey Davy and Count Rumford at the end of last century, but ignored by even the highest scientific men during a period of more than forty years."

"1. There is at present in the material world a universal tendency to the dissipation of mechanical energy. 2. Any restoration of mechanical energy, without more than an equivalent of dissipation, is impossible in inanimate material processes, and is probably never effected by means of organized matter, either endowed with vegetable life or subjected to the will of an animated creature. 3. Within a finite period of time past, the earth must have been, and within a finite period of time to come the earth must again be, unfit for the habitation of man as at present constituted, unless operations have been, or are to be performed, which are impossible under the laws to which the known operations going on at present in the material world are subject."

"It is impossible by means of inanimate material agency, to derive mechanical effect from any portion of matter by cooling it below the temperature of the coldest of the surrounding objects. [Footnote: ] If this axiom be denied for all temperatures, it would have to be admitted that a self-acting machine might be set to work and produce mechanical effect by cooling the sea or earth, with no limit but the total loss of heat from the earth and sea, or in reality, from the whole material world."

"Now I think hydrodynamics is to be the root of all physical science, and is at present second to none in the beauty of its mathematics."

"Every boy... should be able by the age of 12 to write his own language with accuracy and some elegance; he should have a reading knowledge of French, and be able to translate Latin and easy Greek authors, and have some acquaintance with German. Having learned thus the meaning of words... a boy should study Logic, so as to be able to apply his words sensibly."

"To live among friends is the primary essential of happiness."

"It is conceivable that animal life might have the attribute of using the heat of surrounding matter, at its natural temperature, as a source of energy for mechanical effect . . . .The influence of animal or vegetable life on matter is infinitely beyond the range of any scientific enquiry hitherto entered on. Its power of directing the motions of moving particles, in the demonstrated daily miracle of our human free-will, and in the growth of generation after generation of plants from a single seed, are infinitely different from any possible result of the fortuitous concurrence of atoms."

"I need scarcely say that the beginning and maintenance of life on earth is absolutely and infinitely beyond the range of sound speculation in dynamical science."

"Do not imagine that mathematics is hard and crabbed, and repulsive to common sense. It is merely the etherealization of common sense."

"Mathematics is the only true metaphysics."

"Symmetrical equations are good in their place, but 'vector' is a useless survival, or offshoot from quaternions, and has never been of the slightest use to any creature."

"I am afraid I am not in the flight for “aerial navigation”. I was greatly interested in your work with kites; but I have not the smallest molecule of faith in aerial navigation other than ballooning or of expectation of good results from any of the trials we hear of. So you will understand that I would not care to be a member of the aëronautical Society."