Beneficium accipere est Libertatem vendere.

He that accepts a favour, forfeits his liberty. By receiving obligations, particularly if from persons of bad morals, you are precluded the liberty of censuring vices so freely as you might be disposed, or as the subject you are treating might require, especially those vices of which you know them to be guilty; and in public dissensions, you are restrained from maintaining your own opinion, unless it accords with that of your patron. Erasmus, who manifestly held the same opinions on many points of religion, as were taught by Luther and his followers, was yet restrained from openly espousing them, as he received nearly the whole of his income, from persons of the Romish persuasion. Fille qui prend, the French say, son corps vend. The maid who takes presents, has deprived herself of the power of saying «no», or must permit liberties to be taken with her, which she would other wise resist. «Springes to catch woodcocks», says the sententious Polonius, cautioning his daughter against giving credit to Hamlet's promises and presents.