There is in fact a true law namely right reason, which is in accordance with nature, applies to all men and is unchangeable and eternal. ... It will not lay down one rule at Rome and another at Athens, nor will it be one rule today and another tomorrow. But there will be one law eternal and unchangeable binding all times and upon all peoples.
Marcus Tullius CiceroSince an intelligence common to us all makes things known to us and formulates them in our minds, honorable actions are ascribed by us to virtue, and dishonorable actions to vice; and only a madman would conclude that these judgments are matters of opinion, and not fixed by nature.
Marcus Tullius CiceroIf the oarsmen of a fast-moving ship suddenly cease to row, the suspension of the driving force of the oars doesn't prevent the vessel from continuing to move on its course. And with a speech it is much the same. After he has finished reciting the document, the speaker will still be able to maintain the same tone without a break, borrowing its momentum and impulse from the passage he has just read out.
Marcus Tullius Cicero