Here's the (sub)plot of the novel as I conceptualize it
this morning.  Consider a study of the fate (Schicksal) of intellect
in society. With the three protagonists, Katenus, Mengs and Joachim,
intellect (nous) comes to grief in different ways. Joachim is
destroyed by the conflict of intellect and eros; Mengs is destroyed
by the conflict of intellect and (academic) convention. Katenus is
destroyed by the incongruity of truth and society. Katenus says in
effect: "Ich bin in die Welt kommen, dass ich die Wahrheit sagen sollte.
Wer aus der Wahrheit ist, der hoeret meine Stimme." 

King James Version:
John 18:37 Pilate therefore said unto him, Art thou a king then?
Jesus answered, Thou sayest that I am a king.
To this end was I born, and for this cause came I into the world,
that I should bear witness unto the truth.
Every one that is of the truth heareth my voice.

Let me parody this:

The Chief Justice therefore said unto him, Art thou a philosopher then?
Katenus answered, Thou sayest that I am a philosopher.
To this end was I born, and for this cause came I into the world,
that I should bear witness unto the truth.
Every one that is of the truth heareth my voice.

A further parody:

The Chief Justice scatched his nose and adjusted his glasses.
He looked down at Katenus and asked:"You mean to say, you're a 
philosopher?" "Yes, Your Honor," Katenus replied, "That's what I
always wanted to be. I would respectfully say, that it's for the
Court to determine whether a philosopher is what I have become."
"What good does it do anyone to be a philosopher?" "A philosopher,
Your Honor, is one who has learned to recognize the Truth."
"And what good," the Chief Justice asked, "does it do you to have
recognized the Truth?" Katenus replied: "To have recognized the Truth
is prerequisite to telling the Truth. I tell Your Honor the Truth,
and to be told the Truth is this tribunal's most dire need."
"Young man," the youthful judge said to the old, white-haired Katenus,
"You have just gotten yourself in big trouble by telling me the Truth.
I hereby condemn you. I find you guilty of criminal contempt of court.
I sentence you to incarceration of indefinite duration."