With respect to animal diet, let it be considered, that taking away the lives of animals, in order to convert them into food, does great violence to the principles of benevolence and compassion. This appears from the frequent hard-heartedness and cruelty found amongst those persons whose occupations engage them in destroying animal life, as well as from the uneasiness which others feel in beholding the butchery of animals.
"Observations on man, his frame, his duty, and his expectations" - Página 461 http://books.google.com/books?id=MuIQAAAAYAAJ&pg=PA461, de David Hartley - 6, reimpressão, Printed for T.Tegg and son, 1834 - 604 páginas
David Hartley frases e citações
David Hartley: Frases em inglês
On animals. Observations on Man https://archive.org/stream/cu31924029011902#page/n5/mode/2up (1749; 6th edition, 1834), Part I, Chapter III, Section VII.
Observations on Man (1749; 6th edition, 1834), Part II, Chapter III, Section II.