“Among these difficulties is one that has been proposed ever since the world has been a world; ’tis that men suffer without having deserved suffering.  There has been no answer to it yet.  ’Tis the incompatibility of physical and moral evil with the nature of the Eternal Being.  This is how the dilemma is put:  it is either impotence or bad will; impotence, if he wished to hinder evil and could not; bad will, if he could have hindered it and did not will it.  A child would understand that.  It is this that has led people to imagine the fault of the first father of us all, original sin, future rewards and punishments, the incarnation, immortality, the two principles of the Manicheans, the Ormuzd and Ahriman of the Persians, the doctrine of emanations, the empire of light and darkness, metempsychosis, optimism, and other absurdities that have found credit among the different nations of the earth, where there is always to be found some hollow vision of a dream, by way of answer to a clear, precise, and definite fact.

“On such occasions what is the part of good sense?  Why, the part that we took:  whatever the optimists may say, we will reply to them that if the universe could not exist without sensible creatures, nor sensible creatures without pain, there was nothing to do but to leave chaos at peace.  They had got on very well for a whole eternity without any such piece of folly.

“The world a piece of folly!  Ah, my dear, a glorious folly for all that!  ’Tis, according to some of the inhabitants of Malabar, one of the seventy-four comedies with which the Eternal amuses himself.

“Leibnitz, the founder of optimism, tells somewhere how there was in the Temple of Memphis a high pyramid of globes placed one above the others; how a priest, being asked by a traveller about this pyramid and its globes, made answer that these were all the possible worlds, and that the most perfect of them all was at the summit; how the traveller, curious to see this most perfect of all possible worlds, mounted to the top of the pyramid, and the first thing that caught his eyes, as they turned towards the globe at the summit, was Tarquin outraging Lucretia."[221]

Almost every letter reminds us that we are in the very height of the disputing, arguing, rationalistic century.  Diderot delighted in this kind of argument, as Socrates or Dr. Johnson delighted in it.  He was above all others the archetype and representative of the passion for moralising, analysing, and philosophising which made the epoch what it was; but the rest of the world was all in the same vein.  If he came to Paris in a coach from the country, he found a young lady in it, eager to demonstrate that serious passions are nowadays merely ridiculous; that people only promise themselves pleasure, which they find or not, as the case may be; that thus they spare themselves all the broken oaths of old days.  “I took the liberty of saying that I was still a man of those old days.