In my youth I regarded the universe as an open book, printed in the language of equations, whereas now it appears to me as a text written in invisible ink, of which in our rare moments of grace we are able to decipher a small segment.

The greatest temptation for the like of us is: to renounce violence, to repent, to make peace with oneself. Most revolutionaries fell before this temptation, from Spartacus to Danton and Dostoevsky; they are the classical form of betrayal of the cause. The temptations of God were always more dangerous for mankind than those of Satan. As long as chaos dominates the world, God is an anachronism; and every compromise with one’s own conscience is perfidy. When the accursed inner voice speaks to you, hold your hands over your ears….

Einstein's space is no closer to reality than Van Gogh's sky.

The fact is: I no longer believe in my own infallibility. That is why I am lost.

The life we led was a proof of man's capacity for adaptation.I think that even the condemned souls in purgatory after time develop a sort of homely routine.That is ,by the way, why most prison memoirs are unreadable.The difficulty of conveying to the reader an idea of a nightmare world from which he has emerged makes the author depict the prisoner's state of mind as an uninterruped continuity of despair.He fears to appear frivolous or to spoil his effect by admitting that even in the depths of misery cheerfulness keeps breaking in.

There is only one prospect worse than being chained to an intolerable existence: The nightmare of a botched attempt to end it.

In the index to the six hundred odd pages of Arnold Toynbee's A Study of History, abridged version, the names of Copernicus, Galileo, Descartes and Newton do not occur yet their cosmic quest destroyed the medieval vision of an immutable social order in a walled-in universe and transformed the European landscape, society, culture, habits and general outlook, as thoroughly as if a new species had arisen on this planet.