When animal protection has to be implemented in specific legal regulations the assistance of scientific research is usually required, so that concepts such as cruelty and pain are no longer vague or left to the kind of subjective judgements to which Zhuangzi retorted "I am not a fish--how can I know a fish's suffering?" Science also allows appropriate protective rules to be drafted according to the specific needs of different animals.
當保護動物必須落實到具體的法令規範時，往往需要科學研究幫助，如此何謂虐待、痛苦，不再模糊不清，或任人「子非魚，焉知魚之不樂」的主觀認定，也可以進一步針對不同動物的需求，擬定更適合的保護規範。