“You run!” urged Sextus.  “Go now!  Go to my camp in the Aventines.  You will find Norbanus and two freedmen waiting near the Porta Capena; they are wearing farmers’ clothes and look as if they came from Sicily.  They know you.  Say I bade them take you into hiding.”

Galen smiled at him.  “And you?” he asked.

“Narcissus shall smuggle me into the palace.  It is I who will slay Commodus, lest Pertinax should stain his hands.  If they prefer to turn on me, what matter?  Pertinax, if he is to be Caesar, will do better not to mount the throne all bloody.  Let him blame me and then execute me.  Rome will reap the benefit.  Marcia has the praetorian guard well under control, what with her bribes and all the license she has begged for them.  Let Marcia proclaim that Pertinax is Caesar, the praetorian guard will follow suit, and the senate will confirm it so soon after daybreak that the citizens will find themselves obeying a new Caesar before they know the old one is dead!  Then let Pertinax make new laws and restore the ancient liberties.  I will die happy.”

“O youth—­insolence of youth!” said Galen, smiling.  He resumed his mixing of the powders, adding new ingredients.  “I was young once—­young and insolent.  I dared to try to tutor Commodus!  But never in my long life was I insolent enough to claim all virtue for myself and bid my elders go and hide!  You think you will slay Commodus?  I doubt it.”

“How so?”

Sextus was annoyed.  The youth in him resented that his altruism should be mocked.

“Pertinax should do it,” Galen answered.  “If Rome needed no more than philosophy and grammar, better make me Caesar!  I was mixing my philosophy with surgery and medicine while Pertinax was sucking at his mother’s breast in a Ligurian hut.  Rome, my son, is sick of too much mixed philosophy.  She needs a man of iron—­a riser to occasion—­a cutter of Gordian knots, precisely as a sick man needs a surgeon.  The senate will vote, as you say, at the praetorian guard’s dictation.  You have been clever, my Sextus, with your stirring of faction against faction.  They are mean men, all so full of mutual suspicion as to heave a huge sigh when they know that Pertinax is Caesar, knowing he will overlook their plotting and rule without bloodshed if that can be done.  But it can’t be!  Unless Pertinax is man enough to strike the blow that shall restore the ancient liberties, then he is better dead before he tries to play the savior!  We have a tyrant now.  Shall we exchange him for a weak-kneed theorist?”

“Are you ready to die, Galen?”

“Why not?  Are you the only Roman?  I am not so old I have no virtue left.  A little wisdom comes with old age, Sextus.  It is better to live for one’s country than to die for it, but since no way has been invented of avoiding death, it is wiser to die usefully than like a sandal thrown on to the rubbish-heap because the fashion changes.”