The paper deals with the theory of universals of Sebastian Izquierdo, a Spanish Jesuit author working in Rome, as he formulated and defended it in Disputation 17 of his major philosophical work The Lighthouse of Sciences, published in Lyon in 1659. Izquierdo’s discussion centers around three questions: What is universality? Is there some intellect-independent universality? What is the nature of the intellect-dependent universality? Izquierdo’s approach may be seen as a search for the third way between the realism of the Thomists and the Scotists and the nominalism of some Jesuits such as Pedro Hurtado de Mendoza
