From all accounts preserved (and a great deal of his bawdy works written for the entertainment of his (drinking) male friends ("The Crochallen Fencibles") were destroyed after his death) it seems that Burns did not mistreat women. He was a drinker and a philanderer and had the ability to love several women at the same time but he did not beat them as was common practice in his era. (Look up the definition of "Rule of thumb"). It was reputed that he was tall for that time, a good-looking man and "well-hung" and if you consider that to be mistreatment of women, then you maybe you should ask women if size does matter.