Izydora Dąmbska was one of the most creative women-representatives of the Lvov-Warsaw School. The paper presents her extraordinary personality, life, as well as the list of her main works and the greatest scientific achievements. The main area of her interest was the logic of natural language, methodology and the history of Greek semiotics. She gave meticulous analysis of the relation between conventionalism on one hand, and relativism, scepticism and agnosticism on the other. In semiotics, she proposed new approach to the problem of empty names and material implication, of the correct definition of truth, as well as of pragmatic functions of silence and namelessness. In methodology, her reconstruction of the notion of scientific laws is of great importance.