Chemists From France

"Jacob and Monod found that in bacteria, genes are switched on and off by other genes. This led them to distinguish between effector genes and regulatory genes. Effector genes encode effector proteins... which mediate specific cellular functions. Regulatory genes encode proteins called regulatory proteins, which switch the effector genes on or off."

"Jacques Monod... published a paper entitled "Genetic Regulatory Mechanisms in the Synthesis of Protein." Using bacteria as a model system, they made the remarkable discovery that genes can be regulated—that is, they can be switched on and off like a water faucet."

"We might begin with Jacques Monod. Monod was a great figure whose scientific work I much admire, and was, essentially, the creator of modern molecular biology. His reflections on ethics, however, were of a different quality. (...) Monod's conclusions stem from his opinion that the only other possible way to account for the origin of morals - apart from ascribing them to human invention - is by animistic or anthropomorphic accounts such as are given in many religions. And it is indeed true that 'for mankind as a whole all religions have been intertwined with the anthropomorphic view of the deity as a father, friend or potentate to whom men must do service, pray, etc.' (M. R. Cohen, 1931:112). This aspect of religion I can as little accept as can Monod and the majority of natural scientists. It seems to me to lower something far beyond our comprehension to the level of a slightly superior manlike mind."

"There is in science, however, quite a gap between belief and certainty. But would one ever have the patience to wait and to establish the certainty if the inner conviction were not already there?"

"From then on I read avidly the first publications by the "phage-church", and when I entered Lwoff’s department at the Pasteur Institute in 1945, I was tempted to abandon enzyme adaptation in order to join the church myself and work with bacteriophage."

"One day, almost exactly 25 years ago - it was at the beginning of the bleak winter of 1940 - I entered ’s office at the Pasteur Institute. I wanted to discuss with him some of the rather surprising observations I had recently made. I was working then at the old Sorbonne, in an ancient laboratory that opened on a gallery full of stuffed monkeys. Demobilized in August in the Free Zone after the disaster of 1940, I had succeeded in locating my family living in the Northern Zone and had resumed my work with desperate eagerness. I interrupted work from time to time only to help circulate the first clandestine tracts. I wanted to complete as quickly as possible my doctoral dissertation, which, under the strongly biometric influence of Georges Teissier, I had devoted to the study of the kinetics of bacterial growth. Having determined the constants of growth in the presence of different carbohydrates, it occurred to me that it would be interesting to determine the same constants in paired mixtures of carbohydrates. From the first experiment on, I noticed that, whereas the growth was kinetically normal in the presence of certain mixtures (that is, it exhibited a single exponential phase), two complete growth cycles could be observed in other carbohydrate mixtures, these cycles consisting of two exponential phases separated by a complete cessation of growth."

"What I consider completely sterile is the attitude, for instance, of Bertalanffy who is going around and jumping around for years saying that all the analytical science and molecular biology doesn’t really get to interesting results; let’s talk in terms of general systems theory ... there cannot be anything such as general systems theory, it’s impossible. Or, if it existed, it would be meaningless."

"Anything found to be true of E. coli must also be true of elephants."

"The first scientific postulate is the objectivity of nature: nature does not have any intention or goal."

"Jacob and Monod not only outlined a theory of gene regulation, they also discovered the first regulators of gene transcription. These regulators come in two forms—repressors, genes that encode the regulatory proteins that shut genes off, and as later work showed, activators, genes that encode the regulatory proteins that turn genes on."

"If [the emergence of the human species] was unique, as may perhaps have been the appearance of life itself, then before it did appear its chances of doing so were infinitely slender. The universe was not pregnant with life nor the biosphere with man. Our number came up in the Monte Carlo game."

"The universe is not pregnant with life nor the biosphere with man. ... Man at last knows that he is alone in the unfeeling immensity of the universe, out of which he emerged only by chance. His destiny is nowhere spelled out, nor is his duty. The kingdom above or the darkness below: it is for him to choose."

"Lastly, and doubtless always, but particularly at the end of the last century, certain scholars considered that since the appearances on our scale were finally the only important ones for us, there was no point in seeking what might exist in an inaccessible domain. I find it very difficult to understand this point of view since what is inaccessible today may become accessible tomorrow (as has happened by the invention of the microscope), and also because coherent assumptions on what is still invisible may increase our understanding of the visible."

"[U]n symbole n'est, à proprement parler, ni vrai, ni faux; il est plus ou moins bien choisi pour signifier la réalité qu'il représente, il la figure d'une manière plus ou moins précise, plus ou moins détaillée..."

"There you have, then, a theoretical physics which is neither the theory of a believer nor that of a nonbeliever, but merely and simply a theory of a physicist; admirably suited to classify the laws studied by the experimenter, it is incapable of opposing any assertion whatever of metaphysics or of religious dogma, and is equally incapable of lending effective support to any such assertion."

"Every time people cite a principle of theoretical physics in support of a metaphysical doctrine or physical dogma, they commit a mistake, for they attribute to this principle a meaning not its own, an import not belonging to it."

"The one who contributed most to break down the barrier between physical method and metaphysical method, and to confound their domains, so clearly distinguished in the Aristotelian philosophy, was surely Descartes."

"Agreement with experiment is the sole criteria of truth for a physical theory."

"A physical theory reputed to be satisfactory by the sectarians of one metaphysical school will be rejected by the partisans of another school."

"« La Logique peut être patiente, car elle est éternelle. » ("Logic can be patient because it is eternal.") ibid. p. 150"

"The first question we should face is: What is the aim of a physical theory? To this question diverse answers have been made, but all of them may be reduced to two main principles: "A physical theory," certain logicians have replied, "has for its object the explanation of a group of laws experimentally established." "A physical theory," other thinkers have said, "is an abstract system whose aim is to summarize and classify logically a group of experimental laws without claiming to explain these laws... Now these two questions — Does there exist a material reality distinct from sensible appearances? and What is the nature of reality? — do not have their source in experimental method, which is acquainted only with sensible appearances and can discover nothing beyond them. The resolution of these questions transcends the methods used by physics; it is the object of metaphysics. Therefore, if the aim of physical theories is to explain experimental laws, theoretical physics is not an autonomous science; it is subordinate to metaphysics... Now, to make physical theories depend on metaphysics is surely not the way to let them enjoy the privilege of universal consent."

"It is because I know all that science can bring to the world that I shall continue my efforts to ensure that it contributes to the happiness of all men, whether they be white, black, or yellow, and not to their annihilation in the name of some divine mission or other."

"Though Lavoisier generally gets credit for the authorship of this principle [ conservation of mass ], others had conceived it before him, The seventeenth century chemists, notably Helmont, Starkey, and Boyle, had a dawning awareness of the importance of weighing and measuring materials before and after an experimental process, though their methods and measurement devices were not so precise. In 1623, Francis Bacon declared, "..when they perceive that a body which was before manifest to the senses has escaped and disappeared, they should not admit or liquidate the account before it has been shown to them where the body has gone to and into what it has been received." And as early as 450 B.C., Anaxagoras argued, "Wrongly do the Greeks suppose that aught begins or ceases to be; for nothing comes into being or is destroyed; but all is an aggregation or secretion of preexisting things; so that all becoming might more correctly be called becoming mixed, and all corruption, becoming separate.""

"Now Mayow, like Boyle, conceived the air as made up of minute particles, while he restricted himself to two varieties, those, namely, which are necessary to life, called by him "spiritus igno-aereus," and those incapable of supporting respiration or combustion, which are left after the removal of this "spiritus." Since a mixture of saltpetre and sulphur continued burning even under water, he assumed that his igno-aereal particles must also be contained in the salt. Acids too contained the new principle. ...Mayow died in 1679 at the age of thirty-four years; had he lived but a little longer, it can scarcely be doubted that he would have forestalled the revolutionary work of Lavoisier, and stifled the theory of phlogiston at its birth. As it was, his work, though rendered in one of the most luminous and convincing scientific publications of the period, was immediately forgotten, and so proved of little effect on the evolution of our modern chemical system."

"We may lay it down as an incontestible axiom, that, in all the operations of art and nature, nothing is created; an equal quantity of matter exists both before and after the experiment; the quality and quantity of the elements remain precisely the same; and nothing takes place beyond changes and modifications in the combination of these elements. Upon this principle the whole art of performing chemical experiments depends: We must always suppose an exact equality between the elements of the body examined and those of the products of its analysis."

"We must trust to nothing but facts: These are presented to us by Nature, and cannot deceive. We ought, in every instance, to submit our reasoning to the test of experiment, and never to search for truth but by the natural road of experiment and observation."

"It is a maxim universally admitted in geometry, and indeed in every branch of knowledge, that, in the progress of investigation, we should proceed from known facts to what is unknown. ...In this manner, from a series of sensations, observations, and analyses, a successive train of ideas arises, so linked together, that an attentive observer may trace back to a certain point the order and connection of the whole sum of human knowledge."

"Thus, while I thought myself employed only in forming a Nomenclature, and while I proposed to myself nothing more than to improve the chemical language, my work transformed itself by degrees, without my being able to prevent it, into a treatise upon the Elements of Chemistry."

"When I began the following Work, my only object was to extend and explain more fully the Memoir which I read at the public meeting of the Academy of Sciences in the month of April 1787, on the necessity of reforming and completing the Nomenclature of Chemistry. While engaged in this employment, I perceived, better than I had ever done before, the justice of the following maxims of the Abbé de Condillac, in his System of Logic, and some other of his works. "We think only through the medium of words.—Languages are true analytical methods.—Algebra, which is adapted to its purpose in every species of expression, in the most simple, most exact, and best manner possible, is at the same time a language and an analytical method.—The art of reasoning is nothing more than a language well arranged.""

"Here, then: a revolution [in science and chemistry] has taken place in an important part of human knowledge since your departure from Europe... I will consider this revolution to be well advanced and even completely accomplished if you range yourself with us. ...After having brought you up to date on what is happening in chemistry, it would be well to speak to you about our political revolution. We regard it as done and without any possibility of return to the old order."

"The art of concluding from experience and observation consists in evaluating probabilities, in estimating if they are high or numerous enough to constitute proof. This type of calculation is more complicated and more difficult than one might think. It demands a great sagacity generally above the power of common people. The success of charlatans, sorcerors, and alchemists—and all those who abuse public credulity—is founded on errors in this type of calculation."

"The law of conservation of mass was first put into definite form by Lavoisier, in the eighties of the eighteenth century. In considering the fermentation of fruit-juices, wherein carbonic acid gas and alcohol are produced, Lavoisier said:—"We must evidently have a complete knowledge of the analyses and the nature of the substances which can be fermented; for nothing is created, either in the operations of art, or in those of nature, and it may be laid down as a principle that, in every operation there is an equal quantity of matter before and after the operation; ...there is nothing but certain changes, certain modifications. The whole art of experimenting in chemistry rests on this principle; in all experiments one is obliged to assume an actual equality between the principles [that is, elements] of the substances examined and those obtained by the analysis of these substances. Thus, inasmuch as grape-juice yields carbonic acid gas and alcohol, I can affirm that grape juice=carbonic acid gas+alcohol.""

"The extension of Black's method by the physicist Lavoisier led to the downfall of the purely qualitative theory of phlogiston, and gave to chemistry the true methods of investigation, and its first great quantitative law—the law of conservation of matter."

"We are... bound to attach the greatest importance to the preliminary step taken by Lavoisier, who is even more justly called the father of modern chemistry than Kepler is called the father of modern astronomy. The exact claims of Lavoisier to this important place in the history of chemistry have been variously stated: ...since his time, and greatly through his labours, the quantitative method has been established as the ultimate test of chemical facts; the principle of this method being the rule that in all changes of combination and reaction, the total weight of the various ingredients—be they elementary bodies or compounds—remains unchanged. The science of chemistry was thus established upon an exact, a mathematical basis. By means of this method Lavoisier, utilising and analysing the results gained by himself and others before him, notably those of Priestley, Cavendish, and Black, succeeded in destroying the older theory of combustion, the so-called phlogistic theory."

"In 1774 he [ Joseph Priestley ] thought he had obtained nitrous oxide... in 1775 he saw the gas as dephlogisticated air... If we refuse the palm to Priestley, we cannot award it to Lavoisier for the work of 1775... Lavoisier insisted that oxygen was an atomic "principle of acidity"… formed only when that "principle" united with "caloric"... Ignoring Scheele, we can safely say that oxygen had not been discovered before 1774, and we would probably say that it had been discovered by 1777 or shortly thereafter. But... any attempt to date the discovery must inevitably be arbitrary because discovering a new sort of phenomenon is necessarily a complex event, one which involves recognizing both that something is and what it is."

"One of the most fundamental principles of Lavoisier's chemistry was the use of numbers, notably in relation to what we often call today the principle of conservation of mass... The principle implies that the experimenter must not only keep account of all the reacting solids and liquids, but also the gases—that is, all of the products. ...This rule led to quantitative experiments. Lavoisier was not the first person to use numbers in chemistry but he was a pioneer in using such numerical measurements as the basis of his system of chemistry. ...When Lavoisier first announced this law, chemists generally believed in... "phlogiston" which supposedly entered into chemical reactions (such as combustion) but had no weight. It was a radical step, therefore, for Lavoisier to base a system of chemistry on a balance of weights and to maintain that chemistry is not concerned with weightless "substances." ...this was indeed a chemical revolution."

"Marie Curie was at heart a Baconian, boiling tons of crude uranium ore to demolish the dogma of the indestructibility of atoms."

"I am one of those who think like Nobel, that humanity will draw more good than evil from new discoveries."

"There are sadistic scientists who hurry to hunt down errors instead of establishing the truth."

"I was taught that the way of progress was neither swift nor easy."

"Humanity needs practical men, who get the most out of their work, and, without forgetting the general good, safeguard their own interests. But humanity also needs dreamers, for whom the disinterested development of an enterprise is so captivating that it becomes impossible for them to devote their care to their own material profit. Without doubt, these dreamers do not deserve wealth, because they do not desire it. Even so, a well-organized society should assure to such workers the efficient means of accomplishing their task, in a life freed from material care and freely consecrated to research."

"I am among those who think that science has great beauty. A scientist in his laboratory is not only a technician: he is also a child placed before natural phenomena which impress him like a fairy tale. We should not allow it to be believed that all scientific progress can be reduced to mechanisms, machines, gearings, even though such machinery also has its beauty. Neither do I believe that the spirit of adventure runs any risk of disappearing in our world. If I see anything vital around me, it is precisely that spirit of adventure, which seems indestructible and is akin to curiosity."

"I believe international work is a heavy task, but that it is nevertheless indispensable to go through an apprenticeship in it, at the cost of many efforts and also of a real spirit of sacrifice: however imperfect it may be, the work of Geneva has a grandeur that deserves our support."

"You cannot hope to build a better world without improving the individuals. To that end each of us must work for his own improvement, and at the same time share a general responsibility for all humanity, our particular duty being to aid those to whom we think we can be most useful."

"All my life through, the new sights of Nature made me rejoice like a child."

"We must not forget that when radium was discovered no one knew that it would prove useful in hospitals. The work was one of pure science. And this is a proof that scientific work must not be considered from the point of view of the direct usefulness of it. It must be done for itself, for the beauty of science, and then there is always the chance that a scientific discovery may become like the radium a benefit for humanity."

"Life is not easy for any of us. But what of that? We must have perseverance and above all confidence in ourselves. We must believe that we are gifted for something, and that this thing, at whatever cost, must be attained."

"Be less curious about people and more curious about ideas."

"I have no dress except the one I wear every day. If you are going to be kind enough to give me one, please let it be practical and dark so that I can put it on afterwards to go to the laboratory."

"One never notices what has been done; one can only see what remains to be done."