The creation of Bishops' schools, afterwards called seminaries, in which the sons of the clergy were educated, naturally led, in the course of time, to the total exclusion of the other classes.

The policy of the civil Government led to the same end.

Peter the Great laid down the principle that every subject should in some way serve the State--the nobles as officers in the army or navy, or as officials in the civil service; the clergy as ministers of religion; and the lower classes as soldiers, sailors, or tax-payers.

Of these three classes the clergy had by far the lightest burdens, and consequently many nobles and peasants would willingly have entered its ranks.

But this species of desertion the Government could not tolerate, and accordingly the priesthood was surrounded by a legal barrier which prevented all outsiders from entering it.