occasion is, that on my arrival at Vincennes, I was in an agitation
which approached a delirium. Diderot perceived it; I told him the
cause, and read to him the prosopopoeia of Fabricius, written with a
pencil under a tree. He encouraged me to pursue my ideas, and to
become a competitor for the premium. I did so, and from that moment I
was ruined.

All the rest of my misfortunes during my life were the inevitable
effect of this moment of error.

My sentiments became elevated with the most inconceivable rapidity to
the level of my ideas. All my little passions were stifled by the
enthusiasm of truth, liberty, and virtue; and, what is most
astonishing, this effervescence continued in my mind upward of five
years, to as great a degree, perhaps, as it has ever done in that of
any other man. I composed the discourse in a very singular manner, and
in that style which I have always followed in my other works, I
dedicated to it the hours of the night in which sleep deserted me; I
meditated in my bed with my eyes closed, and in my mind turned over and
over again my periods with incredible labor and care; the moment they
were finished to my satisfaction, I deposited in my memory, until I had
an opportunity of committing them to paper; but the time of rising and
putting on my clothes made me lose everything, and when I took up my
pen I recollected but little of what I had composed. I made Madam le
Vasseur my secretary; I had lodged her with her daughter and husband
nearer to myself; and she, to save me the expense of a servant, came
every morning to make my fire, and to do such other little things as
were necessary. As soon as she arrived I dictated to her while in bed
what I had composed in the night, and this method, which for a long
time I observed, preserved me many things I should otherwise have
forgotten.

As soon as the discourse was finished, I showed it to Diderot. He was
satisfied with the production, and pointed out some corrections he
thought necessary to be made. However, this composition, full of force
and fire, absolutely wants logic and order; of all the works I ever
wrote, this is the weakest in reasoning, and the most devoid of number
and harmony. With whatever talent a man may be born, the art of
writing is not easily learned.

I sent off this piece without mentioning it to anybody, except, I
think, to Grimm.

The year following (1750), not thinking more of my discourse, I learned
it had gained