The last book opens with a saying of the elder Cato’s, which Cicero much admires, though he says modestly that he was never able in his own case quite to realise it—­“I am never less idle than when I am idle, and never less alone than when alone”.  Retirement and solitude are excellent things, Cicero always declares; generally contriving at the same time to make it plain, as he does here, that his own heart is in the world of public life.  But at least it gives him time for writing.  He “has written more in this short time, since the fall of the Commonwealth, than in all the years during which it stood”.

He here resolves the question, If honour and interest seem to clash, which is to give way?  Or rather, it has been resolved already; if the right be always the expedient, the opposition is seeming, not real.  He puts a great many questions of casuistry, but it all amounts to this:  the good man keeps his oath, “though it were to his own hindrance”.  But it is never to his hindrance; for a violation of his conscience would be the greatest hindrance of all.

In this treatise, more than in any of his other philosophical works, Cicero inclines to the teaching of the Stoics.  In the others, he is rather the seeker after truth than the maintainer of a system.  His is the critical eclecticism of the ’New Academy’—­the spirit so prevalent in our own day, which fights against the shackles of dogmatism.  And with all his respect for the nobler side of Stoicism, he is fully alive to its defects; though it was not given to him to see, as Milton saw after him, the point wherein that great system really failed—­the “philosophic pride” which was the besetting sin of all disciples in the school, from Cato to Seneca: 

“Ignorant of themselves, of God much more,

* * * * *

Much of the soul they talk, but all awry;
And in themselves seek virtue, and to themselves
All glory arrogate,—­to God give none;
Rather accuse Him under usual names,
Fortune, or Fate, as one regardless quite
Of mortal things".[1]

[Footnote 1:  Paradise Regained.]

Yet, in spite of this, such men were as the salt of the earth in a corrupt age; and as we find, throughout the more modern pages of history, great preachers denouncing wickedness in high places,—­Bourdaloue and Massillon pouring their eloquence into the heedless ears of Louis XIV, and his courtiers—­Sherlock and Tillotson declaiming from the pulpit in such stirring accents that “even the indolent Charles roused himself to listen, and the fastidious Buckingham forgot to sneer"[1]—­so, too, do we find these “monks of heathendom”, as the Stoics have been not unfairly called, protesting in their day against that selfish profligacy which was fast sapping all morality in the Roman empire.  No doubt (as Mr. Lecky takes care to tell us), their high principles were not always consistent with their practice (alas!