History of the Peloponnesian War

On hearing this the first thought of the army was to fall upon the chief authors of the oligarchy and upon all the rest concerned. Eventually, however, they desisted from this idea upon the men of moderate views opposing it and warning them against ruining their cause, with the enemy close at hand and ready for battle.

After this Thrasybulus, son of Lycus, and Thrasyllus, the chief leaders in the revolution, now wishing in the most public manner to change the government at Samos to a democracy, bound all the soldiers by the most tremendous oaths, and those of the oligarchical party more than any, to accept a democratic government, to be united, to prosecute actively the war with the Peloponnesians, and to be enemies of the Four Hundred, and to hold no communication with them.

The same oath was also taken by all the Samians of full age; and the soldiers associated the Samians in all their affairs and in the fruits of their dangers, having the conviction that there was no way of escape for themselves or for them, but that success of the Four Hundred or of the enemy at Miletus must be their ruin.