the ground under my
feet was, strange as it may seem, the conviction that it was impossible
to make my escape from prison.

During the first period of my imprisonment, I, as a youthful and
enthusiastic dreamer, made all kinds of plans for escape, and some of
them seemed to me entirely possible of realisation. Cherishing deceptive
hopes, this thought naturally kept me in a state of tense alarm and
hindered my attention from concentrating itself on more important
and substantial matters. As soon as I despaired of one plan I created
another, but of course I did not make any progress--I merely moved
within a closed circle. It is hardly necessary to mention that each
transition from one plan to another was accompanied by cruel sufferings,
which tormented my soul, just as the eagle tortured the body of
Prometheus.

One day, while staring with a weary look at the walls of my cell, I
suddenly began to feel how irresistibly thick the stone was, how strong
the cement which kept it together, how skilfully and mathematically
this severe fortress was constructed. It is true, my first sensation was
extremely painful; it was, perhaps, a horror of hopelessness.

I cannot recall what I did and how I felt during the two or three months
that followed. The first note in my diary after a long period of silence
does not explain very much. Briefly I state only that they made new
clothes for me and that I had grown stout.

The fact is that, after all my hopes had been abandoned, the
consciousness of the impossibility of my escape once for all
extinguished also my painful alarm and liberated my mind, which was then
already inclined to lofty contemplation and the joys of mathematics.

But the following is the day I consider as the first real day of my
liberation. It was a beautiful spring morning (May 6) and the balmy,
invigourating air was pouring into the open window; while walking back
and forth in my cell I unconsciously glanced, at each turn, with a vague
interest, at the high window, where the iron grate outlined its form
sharply and distinctly against the background of the azure, cloudless
sky.

"Why is the sky so beautiful through these bars?" I reflected as I
walked. "Is not this the effect of the aesthetic law of contrasts,
according to which azure stands out prominently beside black? Or is it
not, perhaps, a manifestation of some other, higher law, according to
which the infinite may be conceived by the human mind only when it