The work of Oliva Sabuco, a Spanish philosopher and Renaissance writer, focuses on a holistic medical philosophy that intertwines physical, psychological, and social health. In her main work, Nueva Filosofía de la Naturaleza del Hombre, she explores the interaction between body and soul, emphasizing the crucial role of emotions and digestion in human health. Sabuco identifies three “pillars of health”: optimism, happiness, and digestive harmony. She argues that these factors promote harmony between the soul and body, which in turn enhances brain and bodily functions. Poor digestion or negative emotions, on the other hand, can disrupt the connection between the brain and body, leading to illness. A central concept in Sabuco’s theory is chilo, a nourishing fluid produced through digestion that sustains the brain. She highlights the importance of balanced nutrition, avoiding overeating, and selecting appropriate foods. Sabuco provides detailed dietary recommendations, including simple and nutritious meals, as well as practices for cleansing the body, such as induced vomiting and fasting. Her approach integrates anatomical knowledge, medical principles, and psychological influences to address and prevent illness. Sabuco advocates for personal responsibility and self-care, embedding her philosophy within a humanistic framework.