From 1894 onwards, the innocent and academic style of Klimt gives way to a more emotionally intense, violent and erotic art. This coincides with rampant changes and challenges in Viennese culture, specifically the emergence of Dionysian dramatic theater and the birth of psychoanalysis. It is interesting to not how profoundly both Freud and Klimt were influenced by the influx of Greek drama at the Burgtheater. Ripping off the mask of assumed rationality and perpetual "progress", both laid bare the disturbing subconscious drives that  threaten to consume-- and destroy-- civilization. Both Freud and Klimt hold Eros ( the life instinct) and Tod  (the death instinct) in perpetual tension and use water as a symbol of the unconscious depths.

In 1894,  Klimt was commissioned to create a series of three paintings to decorate the Great Hall of the  University of Vienna. ostensibly to celebrate the achievements of higher education. As the images emerged, however, they were anything but a celebration of the "triumph of rationality". Instead,  Jurisprudence, Philosophy and Medicine (tragically destroyed in WWII by the Nazis)  created a scandal and were deemed "pornographic" for their vivid and cynical perspective on the darkness of their vision, a world almost consumed by fear, terror, disease and despair.

Klimt bought the paintings back, and the difficulties he had with censorship led him to found the Secessionist movement with its  emphasis on Art as Truth and Auguste Rodin as a supporter.  Klimt created the icon of Pallas Athena (above) as a figure meant to embody the search for wisdom and truth. In her hands she holds a red haired woman who becomes the symbol of Naked Truth.
His Nuda Verita (1899) defined his bid to further shake up the establishment.  In 1899, this image became the poster for the movement,  holding the mirror of truth, with  a quotation by Schiller above, "If you cannot please everyone with your deeds and your art, please a few. To please many is bad."

Recommended reading: Eric Kandel, The Age of Insight: The Quest to Understand the Unconscious in Art, Mind, and Brain, from Vienna 1900 to the Present