From, Paul Levy, Quelques aspets de la pens'ee d'un mathematicien, Albert Blanchard, Paris 1970.

``J'ai alors une impression comparable `a celle d'un explorateur qui, arriv'e au sommet d'une montagne, d'ecouvre brusquement un paysage nouveau. Imaginons par example qu'un nomm'e Dupont, ayant fait le premier l'ascension du Br'event, en rapporte un croquis de la cha^ine du Mont--Blanc vue de ce sommet, et le publie. Imaginons que Durand, faisant `a son tour la m^eme ascension, 'ecrive: `J'ai fait une d'ecouverte qui avait 'echapp'e `a Dupont: l'Aiguille Verte, les Grandes Jorasses, l'Aiguille du Midi et le Mont--Blanc, vus du Br'event, se succ`edent de gauche `a droite dans l'ordre indiqu'e.' Dupont n'est--il pas en droit de r'epondre: `cela va sans dire. Il n'y a qu'a regarder mon dessin'? Mais Durand peut r'epliquer: `Cela va encore mieux en le disant, et c'est moi qui l'ai dit.''

My translation:

``I then had an impression like that of an explorer who, having climbed the summit of a mountain suddenly discovers new scenery. Imagine, for example, that a certain Smith, having been the first to climb up the Br'event, brings back a sketch of the Mont--Blanc range seen from this summit. Imagine that Jones, having in turn made the climb, writes: `I made a discovery that escaped Smith's attention: The Aiguille Verte, the Grandes Jorasses, the Aiguille du Midi, and the Mont--Blanc, as seen from the Br'event, follow each other in the indicated order.' Doesn't Smith have the right to respond: `That goes without saying. One only has to look at my drawing?' But Jones can reply: `And it goes even better if you say it, and I'm the one who did.'

In my life, I have often been Smith... One day a Mr. Jones claimed to discover a theorem that I had failed to state. I happened to say to him: `I knew it, it's an obvious case of a well known theorem,' or more simply, `it goes without saying.' One day, Jones said to me: `And it goes even better when you say it.' It occurred to me that he might be rightldots I then promised myself that in the future I would describe the essential properties of the scene that I observed from the mountain top. In any case, I stayed upset with this Mr.~Jones, who in 1943, in a case of bad temper, published a letter putting my sincerity in doubt. He has no doubt forgotten it, and I want to forget it as well. I now have better relations with him. If I have spoken of this incident, it is to say that I have always been sincere and I will always be so. It should be understood that I am only speaking of my own personal history, from my subjective standpoint. Thus, I will later relate why I did not publish a result in 1902 that Ces`aro published in 1906. It is clear that history can only attribute it to Ces`aro; but I can only hope that I will be believed when I say that I knew it in 1902. In general, it is understood that, if I say of a theorem of Jones that I knew it before him, that does not mean that one is wrong to attribute it to Jones. I only had to publish it earlier and history will attest to the fact that I didn't. But I often regretted it. As a psychoanalyst would say, I have had complexes because of my regrets and I have worked them out by talking about them.''