It should not surprise anyone if abandoning here the style proper to historical narrative I express myself in a more declamatory and ambitious manner.
Some, however, may reproach me for writing with undue animosity, it being rather my first duty to throw a veil over the offences of the Greeks.
Now neither do I think that a man who is timid and afraid of speaking his mind should be regarded by those qualified to judge as a sincere friend, nor that man should be regarded as a good citizen who leaves the path of truth because his is afraid of giving temporary offence to certain persons; and in a writer of political history we should absolutely refuse to tolerate the least preference for anything but the truth.
For inasmuch as a literary record of facts will reach more ears and last longer than occasional utterances, a writer should attach the highest value to truth and his readers should approve his principle in this respect.
In times of danger it is true those who are Greek should help the Greeks in every way, by active support, by cloaking faults and by trying to appease the anger of the ruling power, as I myself actually did at the time of the occurrences;
but the literary record of the events meant for posterity should be kept free from any taint of falsehood, so that instead of the ears of readers being agreeably tickled for the present, their minds may be reformed in order to avoid falling more than once into the same errors.
Walbank Commentary