The Silence of Secundus

The Emperor orders his executioner to take Secundus away, ostensibly to have him killed. But actually secretly gives him instructions, to give Secundus one final chance to speak to save his life,. but only to kill him if he actually does speak. So of course Secundus doesn't buckle and refuses to speak even when the axe is right at his neck. Now no reason whatever is given for Secundus's silence, except for the fact that he is a Pythagorean philosopher.