Carlyle's "History of Friedrich II of Prussia" BOOK VIII.
Page: 44

"SCHULENBURG: If your Highness behave well, the King will accord
what you want: but it is absolutely necessary to begin by that.--
PRINCE: I do nothing that can displease the King.--
SCHULENBURG: It would be a little soon yet! But I speak of the
future. Your Highness, the grand thing I recommend is to fear God!
Everybody says, you have the sentiments of an honest man;
excellent, that, for a beginning; but without the fear of God,
your Highness, the passions stifle the finest sentiments.
Must lead a life clear of reproach; and more particularly on the
chapter of women! Need not imagine you can do the least thing
without the King's knowing it: if your Highness take the bad road,
he will wish to correct it; the end will be, he will bring you
back to live beside him; which will not be very agreeable.--
PRINCE: Hmph, No!--SCHULENBURG: Of the ruin to health I do not
speak; I--PRINCE: Pooh, one is young, one is not master of that;"
--and, in fact, on this delicate chapter, which runs to some
length, Prince answers as wildish young fellows will; quizzing my
grave self, with glances even at his Majesty, on alleged old
peccadilloes of ours. Which allegations or inferences I rebutted
with emphasis. "But, I confess, though I employed all my rhetoric,
his mind did not seem to alter; and it will be a miracle if he
change on this head." Alas, General! Can't be helped, I fear!

"He said he was not afraid of anything so much as of living
constantly beside the King.--SCHULENBURG: Arm yourself with
patience, Monseigneur, if that happen. God has given you sense
enough; persevere to use it faithfully on all occasions, you will
gain the good graces of the King.--PRINCE: Impossible; beyond my
power, indeed, said he; and made a thousand objections.--
SCHULENBURG: Your Highness is like one that will not learn a trade
because you do not already know it. Begin; you will certainly
never know it otherwise! Before rising in the morning, form a plan
for your day,"--in fact, be moral, oh, be moral!

His Highness now got upon the marriages talked of for him;
an important point for the young man. He spoke, hopefully rather,