  This paper gives a condition of the expression of generality in mathematics
from the application of L\"owenheim-Skolem theorem to Zermelo's axioms. It
gives an example of an "expression problem" from Gauss's Disquisitiones
Arithmeticae and caracterizes the used of sets in it.---L'article d\'egage une
condition de l'expression de la g\'en\'eralit\'e en math\'ematiques \`a partir
de l'application du th\'eor\`eme de L\"owenheim-Skolem aux axiomes de Zermelo.
Il donne un exemple de "probl\`eme d'expression" \`a partir des Disquisitiones
Arithmeticae de Gauss, d\'egageant ainsi une condition du recours aux
ensembles.
