Inhibition, Symptoms and Anxiety (1926) is one of Sigmund Freud’s most significant later works, marking a pivotal shift in his theoretical framework and offering a revised understanding of anxiety, its origins, and its role in psychological functioning. In this groundbreaking text, Freud revisits and revises some of his earlier ideas, particularly those outlined in his earlier work The Interpretation of Dreams and his topographic model of the mind. Here, he introduces a new perspective on anxiety, moving away from his earlier view of anxiety as repressed libido and instead framing it as a response to perceived threats or dangers. Freud begins by distinguishing between three key concepts: inhibition, symptoms, and anxiety. He defines inhibition as a restriction or limitation of normal functioning, often stemming from unconscious conflicts. Symptoms, on the other hand, are manifestations of these conflicts, serving as compromise formations between repressed desires and the demands of reality. Anxiety, in Freud’s revised view, is not merely a byproduct of repression but a central mechanism in the psyche’s response to danger. One of the most important contributions of this work is Freud’s reconceptualization of anxiety as a signal function of the ego. He argues that anxiety arises when the ego perceives a threat, whether from external dangers or internal impulses that could lead to conflict or punishment. This "signal anxiety" serves as a warning, prompting the ego to take defensive measures to avoid or mitigate the perceived danger. This theory represents a significant departure from Freud’s earlier view of anxiety as the direct result of repressed libido, offering a more nuanced and dynamic understanding of its role in mental life.