M.C. Escher self-portrait

The geometry of space translates to a reoccurring theme in my creations: the tessellation... had been considered solely in theory prior to me, some say. I diverged from traditional approaches, and chose instead to find solutions visually

---Interview (January 17th, 1971)

The ideas... often bear witness to my amazement and wonder at the laws of nature which operate in the world around us... By keenly confronting the enigmas that surround us, and by considering and analyzing the observations that I had made, I ended up in the domain of mathematics. Although I am absolutely without training or knowledge in the exact sciences, I often seem to have more in common with mathematicians than with my fellow-artists.

---The Graphic Work

At first I had no idea at all of the possibility of building up my figures. I did not know any "ground rules" and tried, almost without knowing what I was doing, to fit together congruent shapes that I attempted to give the form of animals. Gradually, designing new motifs became easier as a result of my
study of the literature on the subject, as far as this was possible for
someone untrained in mathematics, and especially as a result
of my putting forward my own layman's theory, which forced me to think through the possibilities. It remains an extremely absorbing activity, a real
mania to which I have become addicted, and from which I sometimes find
it hard to tear myself away.

---Regular Division of the Plane