I am always wandering around in enigmas. There are young people who constantly come to tell me: you, too, are making Op Art. I haven't the slightest … - M. C. Escher

When the sea is calm, the landscape (seascape) seems simple and even monotonous, sometimes with a distant, sometimes with a close coastline, but usually with no land in sight at all. You feel 'free', not only free of care, but also free of the solidity of the earth's crust. It is a wonderful sensation, feeling the liquidity of the water under the ship. This salutary freedom is constantly present, on deck by day, in bed at nights. The movements of the ship vary from a gentle rocking to swinging and hurtling; you are never motionless while at sea. Then you start to observe and assimilate all these natural phenomena surrounding you: the infinite variety of the waves and the swell of the sea, and for the first time in ages you look again at the heavenly bodies, the sun, the moon and the stars, and you see the living creatures in and over the sea, the fish and the birds.

«It is impossible for the inhabitants of different worlds to walk or sit or stand on the same floor, because they have differing conceptions of what is horizontal and what is vertical. Yet they may well share the use of the same staircase. On the top staircase illustrated here, two people are moving side by side and in the same direction, and yet one of them is going downstairs and the other upstairs. Contact between them is out of the question because they live in different worlds and therefore can have no knowledge of each other's existence.»

What I give form to in daylight is only one per cent of what I have seen in darkness.