Oswald's exposure to Hindu vegetarianism in India influenced his philosophy which he describes in The Cry of Nature or An Appeal to Mercy and Justice on Behalf of the Persecuted Animals, published in 1791.
Oswalds møde med hinduistisk vegetarianisme i Indien fik stor indflydelse på hans filosofi, som han beskriver i The Cry of Nature or An Appeal to Mercy and Justice on Behalf of the Persecuted Animals, udgivet i 1791.