A driving assistance system includes at least one receiving module designed to receive perception data from a driving environment, a control module designed to control an on-board system, a conversion module designed to generate, on the basis of the perception data, a plurality of instances of classes of an ontology stored by the driving assistance system and defining relations between classes, and a reasoning tool designed to deduce, on the basis of the ontology, at least one property of an instance of the plurality. The control module is designed to control the on-board system on the basis of the deduced property.