Symbolism of the work is quite transparent:  The human ascending and reaching the ideal, and cognition of his spirit represented by walking up the stairs.  The pages of the symbolic book are the stages of his spirit.  The bird's feather and the flight of Icarus illustrate the idea of the flight of human mind and spirit.

The idea of self-cognition comes also from Leonardo da Vinci's drawing, "Vitruvian Man."  According to Leonardo's description, the drawing was created to determine the proportions of the human male body as it was depicted in the tractates of the antique architect Vitruvius.  The drawing is often used as the symbol of the symmetry of the human body, and further on, the Universe.  Later, in accordance to that method, the well-known architect Le Corbusier created his own scale of proportions, which influenced the aesthetics of 20th century architecture.