The third edition of this work offers a deep synthesis of reflections on politics, ideology, and doctrines, reflecting the author's interest in social sciences from an interdisciplinary perspective. It includes preliminary notes that analyze previous editions and their evolution, as well as a preface that highlights the key points of this edition and invites readers to engage with it. The main content of the book focuses on personalism, emphasizing the importance of the subject in modernity and exploring its ontology. It presents a diachronic line that examines the main tenets of personalism, highlighting the contributions of thinkers like Maritain, Berdiaeff, and Mournier, and concludes with a reflection on the influence of Hispanic American thinkers within this tradition.