This thesis, titled Hortus Diabolicus - Allegories of the Wild Mind, explores inner states of the mind through the allegory of a garden. Through a series of paintings, the concept of the garden is examined as a symbol for the inner worlds of the mind, often filled with discomfort, fear, and chaotic emotions. Inspiration is drawn from personal experiences related to Gorski kotar, the nature and people of that region, as well as from the iconography of historical artworks such as those by Hieronymus Bosch. Using a painting approach based on abstract and expressionist art, the works lie at the intersection of figuration and abstraction, with a focus on exploring the movement of color as a key element of the image. The fundamental influence is the color theory of Wassily Kandinsky, which provides a theoretical framework for understanding color and its impact on artistic expression. The series of works focuses on the grammar of painting and the relationship between the movement of colors and brushstrokes, and investigates how the overlap of brushstrokes can impact the harmony of the piece. By combining techniques, the allegorical garden is portrayed as a place of wilderness, illness, and emotion, contrasting with the traditional idea of a paradise garden. The conceptual framework relies on Carl Gustav Jung’s teachings on the collective unconscious and the process of integrating the mind. As a whole, the thesis emphasizes the importance of embracing all aspects of the inner world, including the darker, more painful, and often rejected elements, and their transformative power.