The cause of all these evils was the lust for power arising from greed and ambition; and from these passions proceeded the violence of parties once engaged in contention.

With reference to the narrative of events, far from permitting myself to derive it from the first source that came to hand, I did not even trust my own impressions, but it rests partly on what I saw myself, partly on what others saw for me, the accuracy of the report always being tried by the most severe and detailed tests possible. My conclusions have cost me some labour from the want of coincidence between accounts of the same occurrences by different eye-witnesses, arising sometimes from imperfect memory, sometimes from undue partiality for one side or the other.

What made the war inevitable was the growth of Athenian power and the fear which this caused in Sparta.

History is Philosophy teaching by example.

... Athenians are addicted to innovation. They are daring beyond their judgment they toil on with little opportunity for enjoying, being ever engaged in getting, they were born into the world to take no rest themselves, and to give none to others.

You can now, if you choose, employ your present success to advantage, so as to keep what you have got and gain honour and reputation besides, and you can avoid the mistake of those who meet with an extraordinary piece of good fortune, and are led on by hope to grasp continually at something further, through having already succeeded without expecting it.

...knowing the secret of happiness to be freedom, and the secret of freedom a brave heart, not idly to stand aside from the enemy's onset.