Wikipedia says this about Carl Linnaeus:
In his book Dieta Naturalis, he said, "One should not vent one's wrath on animals, Theology decree that man has a soul and that the animals are mere 'aoutomata mechanica,' but I believe they would be better advised that animals have a soul and that the difference is of nobility."
I assume "Dieta Naturalis" refers to a diet, in the culinary sense? I can't find anything online about this book. What was it about?
The book is Diæta naturalis, and was a series of lectures he had published in 1733 about how to live a healthy, "natural" life. There is an edition from the 1950s but it doesn't seem to have been translated into English. I have no idea what is in it, but if you Google Diæta rather than Dieta you get many more results.