"His speech is hesitant because he is used to crossing out his words. It is true that after several redrafts, his style may be crystal clear. But when he takes the floor, he no longer has any means at his disposal to correct his stumbling speech."

"Writing is a strange and solitary activity."

"A novelist's lack of awareness of and critical distance to his own body of work is due to a phenomenon that I have noticed in myself and many others: as soon as it is written, every new book erases the last one, leaving me with the impression that I have forgotten it. I thought I was writing books one after the other in a disjointed way, in successive bouts of oblivion, but often the same faces, the same names, the same places, the same phrases keep coming back in book after book, like patterns on a tapestry woven while half asleep. While half asleep or while daydreaming. A novelist is often a sleepwalker, so steeped is he in what he must write, and it is natural to worry when he crosses the road in case he is run over. Do not forget, though, the extreme precision of sleepwalkers who walk over roofs without ever falling off."

"I always think twice before reading the biography of a writer I admire. Biographers sometimes latch onto small details, unreliable eyewitness accounts, character traits that appear puzzling or disappointing – all of which is like the crackling sound that messes with radio transmissions, making the music and the voices impossible to hear. It is only by actually reading his books that we gain intimacy with a writer. This is when he is at his best and he is speaking to us in a low voice without any of the static."

"L. Walras first formulated the state of the economic system at any point of time as the solution of a system of simultaneous equations representing the demand for goods by consumers, the supply of goods by producers and the equilibrium condition that supply equal demand on every market."

"I had become interested in economics, an interest that was transformed into a lifetime dedication when I met with the mathematical theory of general economic equilibrium."

"Perhaps as important is the relation between the existence of solutions to a competitive equilibrium and the problems of normative or ."

"... en matière scientifique, on a souvent des prédécesseurs beaucoup plus anciens qu'on ne le pense a priori."

"A dense film of a conventional surfactant is quite impermeable. On the other hand, a dense film of Janus grains always has some interstices between the grains, and allows for chemical exchange between the two sides; "the skin can breathe". This may possibly be of some practical interest."

"Benjamin Franklin performed a beautiful experiment using surfactants; on a pond at Clapham Common, he poured a small amount of oleic acid, a natural surfactant which tends to form a dense film at the water-air interface. He measured the volume required to cover all the pond. Knowing the area, he then knew the height of the film, something like three nanometers in our current units. This was to my knowledge the first measurement of the size of molecules. In our days, when we are spoilt with exceedingly complex toys, such as nuclear reactors or synchrotron sources, I particularly like to describe experiments of this Franklin style to my students. Surfactants allow us to protect a water surface, and to generate these beautiful soap bubbles, which are the delight of our children."

"Le vrai point d'honneur [d'un scientifique] n'est pas d'être toujours dans le vrai. Il est d'oser, de proposer des idées neuves, et ensuite de les vérifier."

"The final lines are not mine: they come from an experiment on soft matter, after Boudin… An English translation might run like this:"

"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."

"Two seemingly incompatible conceptions can each represent an aspect of the truth … They may serve in turn to represent the facts without ever entering into direct conflict."

"It seems a little paradoxical to construct a configuration space with the coordinates of points which do not exist."

"Admettant que la particule possède une vibration interne qui permet de l'assimiler à une petite horloge, je supposais que cette horloge se déplaçait dans son onde de façon que sa vibration interne reste constamment en phase avec celle de l'onde : c'est le postulat de l'accord des phases."

"The actual state of our knowledge is always provisional and … there must be, beyond what is actually known, immense new regions to discover."

"The history of science shows that the progress of science has constantly been hampered by the tyrannical influence of certain conceptions that finally came to be considered as dogma. For this reason, it is proper to submit periodically to a very searching examination, principles that we have come to assume without any more discussion."