Sentence:  I envy those chroniclers who assert with reckless but sincere <WSD>abandon</WSD>: 'I was there. I saw it happen. It happened thus.' 
Meaning of the word marked with <WSD> tags:  A yielding to natural impulses or inhibitions; freedom from artificial constraint, with loss of appreciation of consequences. (Early 19th century.)<ref name=SOED/><ref>(page=2).</ref>