From V. I. Ger'e, Sbornik pisem i memorialov Leïbnitsa otnosyashchikhsya k Rossii i Petru Velikomu, Saint Petersburg, 1873. Nos. 34-39. To read the original French, click 'keep reading' below.
Leibniz to Sparwenfeld, 13 July, 1698
What do you have to say, Sir, of the voyage of the Tsar of Muscovy, and of the grand plan he has to de-barbarianize his nation? Is this not something quite extraordinary?
Leibniz to Sparwenfeld, 27 December, 1698
People criticize me when I attempt to take leave of the study of mathematics, and they tell me that I am wrong to abandon solid and eternal truths in order to study the changing and perishable things that are found in history and its laws.
Leibniz to Sparwenfeld, 14 (24) March, 1699
The Tsar is without a doubt a great prince, and it is a great pity that domestic strife has recently forced him to resort to such terrible executions. It is reported that his principal aides, both ecclesiastical as well as secular, were obligated to take a direct part in the execution of some criminals. This is a custom that still retains a bit of the Scythian, and I am surprised that this does not put the churchmen in that country out of sorts. But this hardly matters; what I am afraid of is that such tortures, far from squelching the animosity, will in fact only sharpen them by a sort of contagion. The children, parents, and friends of those executed are left with a wounded spirit, and it is a dangerous maxim that says: oderint, dum metuant. I greatly hope that God will protect this prince and that his heir will achieve what he has begun, namely, to civilize the nation.
Sparwenfeld to Leibniz, Amsterdam, 9 April, 1699
It is true, Sir, that the Tsar is a great warrior, and that he prefers to continue to make war rather than to make peace with the infidels. He was even not very happy with me, because I encouraged making peace with the Turks. It is certain that the domestic strife was very great during his absence, and that he was obligated to take a direct part in the execution of criminals. But there is nothing to fear from the friends of those executed, for the custom is to send the wives, children, and even all of the relatives of those who have been tortured to death to Siberia, or to some other far-away country. I learned many things about what happened in Moscow recently, and I believe, Sir, that you are also well informed.
I believe that it is true that His Majesty the Tsar, when in Vienna, agreed to give the German Jesuits open passage to China across his territory; but I doubt, as you do, as to the outcome of this.
Sparwenfeld to Leibniz, Amsterdam, 5 July, 1699
Regarding what you said, Sir, about a certain Muscovite custom that reeks a bit of the Scythian, I cannot refrain from telling you that I recall being in a certain place, not far from the city of Novgorod in Muscovy, where I came across a mountain called Cholobgora, which is to say Slave Mountain, and at the foot of this mountain a small river called Cholobreca, or Slave River. And when I inquired as to the origin of this name, the inhabitants related that, a long time ago, the men of this place had left in order to make war in distant lands, and that after a long absence the women, having befriended the slaves and servants of their husbands, attempted to prevent the return of these latter into their own country. But the husbands beat and chased away these sevants using no other weapons than their whips. In a word, they related to me the whole story that we find in Justin about the Scythian slaves who fought against the return of their masters into their country. However, it must be noted, Sir, that these people understand neither Greek nor Latin, having no knowledge of antiquity. From which I conclude that this region around Novgorod was part of ancient Scythia, as you have remarked.