Le concept linguistique de vicariance n’a jamais été délimité précisément. Le but de cette thèse est donc d’une part de définir une notion de linguistique générale, et d’autre part d’étudier les principaux mots vicariants du français, de l’italien, de l’espagnol et du portugais. Nous verrons que les mots vicariants se caractérisent par leur incomplétude, par leur sémantisme abstrait et par le fait d’être sémantiquement neutres par rapport à leur antécédent. Nous étudierons dans cette perspective le verbe faire, le que vicariant, les pronoms relatifs et interrogatifs, chose, truc, machin et bidule, les pronoms personnels de troisième personne, les pronoms y et en, les pronoms démonstratifs et tous et tout, et, à chaque fois, leurs équivalents italiens, espagnols et portugais. Notre approche se fondera essentiellement sur la psychomécanique du langage de Gustave Guillaume, qui présente l’avantage d’être une linguistique intégrale, puisqu’elle prend en compte aussi bien la langue que la transition de cette dernière au discours. La psychomécanique du langage postule que le sens correspond à un mouvement de pensée, et c’est ce mouvement de pensée que nous essaierons de reconstruire pour chacun des mots vicariants que nous avons énumérés. / The linguistic concept of vicariancy has never been defined precisely. The purpose of this thesis is therefore on the one hand to determine a notion of general linguistics, and on the other hand to study the main vicariant words in French, Italian, Spanish and Portuguese. We will see that vicariant words can be characterized by their incompleteness, by their abstract semantism and by the fact of being semantically neutral with regard to their antecedent. We will study from this point of view the verb faire, the que vicariant, the relative and interrogative pronouns, chose, truc, machin and bidule, the third-person pronouns, the pronouns y and en, the demonstrative pronouns and tous and tout, and, each time, their Italian, Spanish and Portuguese equivalents. Our approach is essentially based on Gustave Guillaume’s psychomecanics of language, which has the advantage of being a complete linguistics, since it considers the langue as well as the transition from this one to the discours. The psychomecanics of language postulates that the sense can be described as a movement of thought, and we will try to reconstruct this movement of thought for each one of the vicariant words we have enumerated.The linguistic concept of vicariancy has never been defined precisely. The purpose of this thesis is therefore on the one hand to determine a notion of general linguistics, and on the other hand to study the main vicariant words in French, Italian, Spanish and Portuguese. We will see that vicariant words can be characterized by their incompleteness, by their abstract semantism and by the fact of being semantically neutral with regard to their antecedent. We will study from this point of view the verb faire, the que vicariant, the relative and interrogative pronouns, chose, truc, machin and bidule, the third-person pronouns, the pronouns y and en, the demonstrative pronouns and tous and tout, and, each time, their Italian, Spanish and Portuguese equivalents. Our approach is essentially based on Gustave Guillaume’s psychomecanics of language, which has the advantage of being a complete linguistics, since it considers the langue as well as the transition from this one to the discours. The psychomecanics of language postulates that the sense can be described as a movement of thought, and we will try to reconstruct this movement of thought for each one of the vicariant words we have enumerated.