"At all events, as the accommodation of the sick and the preservation of mens lives are the first and great objects to be consulted"
From George Washington to John Hancock, June 8th, 1778
First, since the reading level at which Washington wrote was so high (grade 20 on average) and that he would often continue his thoughts into following sentences, it would at least be justified to post the entire statement. As an example, if you excluded the last sentence of the paragraph I provided, you could mistakingly believed Washington did think human nature could be changed, even though it is apparent he did not.
Furthermore, although this may be true, it still did not keep his men from abandoning posts due to half pay. Just for context, for those other then you who do not know, Washington wrote that letter after congress reduced pay for the army while mistakingly believing the virtue of the revolution would be enough to convince men to fight. It was not.