French Mathematician Quotes
Sneezing absorbs all the functions of the soul just as much as the [sexual] act, but we do not draw from it the same conclusions against the greatness of man, because it is involuntary; although we bring it about, we do so involuntarily. It is not for the sake of the thing in itself but for another end, and is therefore not a sign of man's weakness, or his subjection to this act.
There is a certain way of searching for the truth in mathematics that Plato is said first to have discovered; Theon named it analysis, and defined it as the assumption of that which is sought as if it were admitted and working through its consequences to what is admitted to be true. This is opposed to synthesis, which is the assuming what is admitted and working through its consequences to arrive at and to understand that which is sought.
The infinitely small neither have nor can have theory; it is a dangerous instrument in the hands of beginners [...] anticipating, for my part, the judgement of posterity, I would dare predict that this method will be accused one day, and rightly, of having retarded the progress of the mathematical sciences.
Mathematicians have never been in full agreement on their science, though it is said to be the science of self-evident verities — absolute, indisputable and definitive. They have always been in controversy over the developing aspects of mathematics, and they have always considered their own age to be a period of crisis.
Indeed every mathematician knows that a proof has not been "understood" if one has done nothing more than verify step by step the correctness of the deductions of which it is compose d and has not tried to gain a clear insight into the ideas which have led to the construction of this particular chain of deductions in preference to every other one.
Everything considered, mathematicians should have the courage of their most profound convictions and thus affirm that mathematical forms indeed have an existence that is independent of the mind considering them.... Yet, at any given moment, mathematicians have only an incomplete and fragmentary view of this world of ideas.
We can take pride in the fact that there is no science as certain as ours [alchemy] because it teaches by experience which is the mother, the source and the universal cause of all knowledge: and it is for the lack of this that Aristotle and the other philosophers have wondrously failed in their philosophy.
It is to the influence of the opinion of those whom the multitude judges best informed and to whom it has been accustomed to give its confidence in regard to the most important matters of life that the propagation of those errors [pertaining to errors of truth] is due which in times of ignorance have covered the face of the earth.
In the machine for a new use of gunpowder, which is described in the 'Acta Eruditorum' for the month of September, 1688, the first desideratum was, that the gunpowder fired in the bottom of the tube AA should fill the whole cavity with flame, so that the air might be entirely expelled from it, and the tube remain a perfect vacuum beneath the piston BB. But there it was mentioned, that the desired effect could not be sufficiently attained... But hitherto such attempts have been in vain; and always, after the flame of the gunpowder is extinguished, about a fifth part of the air remains in the tube AA.