'Elémens de Newton' by Voltaire (protest at Descartes and the selfish cruelty of our species):

There is in man a disposition to compassion as generally diffused as his other instincts. Newton had cultivated this sentiment of humanity, and he extended it to the lower animals. With Locke he was strongly convinced that God has given to them a proportion of ideas, and the same feelings which he has to us. He could not believe that God, who has made nothing in vain, would have given to them organs of feeling in order that they might have no feeling.

He thought it a very frightful inconsistency to believe that animals feel and at the same time to cause them to suffer. On this point his morality was in accord with his philosophy. He yielded but with repugnance to the barbarous custom of supporting ourselves upon the blood and flesh of beings like ourselves, whom we caress, and he never permitted in his own house the putting them to death by 'recherchées' modes of killing for the sake of making the food more delicious. This compassion, which he felt for other animals, culminated in true charity for men. In truth, without humanity, a virtue which comprehends all virtues, the name of philosopher would be little deserved.

He said some very damning things about eating animals - but he continued to do it, and raise animals for slaughter on his land. He pushed vegetarianism forward, but it wasn't an age when Europeans particularly followed through in their practice.

That came later, with the revolution.

I know you know about "Vegetarianism: The Story So Far", but I'll leave up the relevant episode in case folk are interested - I have a chat with an expert in Voltaire (who is himself vegan and has published on vegetarian history) in Voltaire's favourite caf

"Men fed upon carnage, and drinking strong drinks, have all an impoisoned and arid blood which drives them mad in a hundred different ways."

Voltaire (1694-1778)