I just merely writing from a page in Michael Crichton's book: Congo. Always the brilliant in making a storyline (you all seen Jurassic Park), he always struck in the best of way.
Over the years, scientists had evolved a standard defense acceptable to the courts. Researches claimed that their experiments had the goal of bettering the health and welfare of mankind, a higher priority than animal welfare. They pointed out that no one objected to animals being used as beasts of burden or for agricultural work--a life of drudgery to which animals had been subjected for thousands of years. Using animals in scientific experiments simply extended the idea that animals were the servants of human enterprises.
In addition, animals were literally brutes. They had no self-awareness, no recognition of their existence in nature. This meant, in the words of philosopher George H. Mead, that "animals have no rights. We are at liberty to cut off their lives, there is no wrong committed when an animal's life is taken away. He has not lost anything..."
Many people were troubled by these views, but attempts to establish guidelines quickly ran into logical problems. The most obvious concerned the perceptions of animals further down the phylogenetic scale. Few researchers operated on dogs, cats, and other mammals without anesthesia, but what about annelid worms, crayfish, leeches, and squid? Ignoring these creatures was a form of "taxonomic discrimination". Yet if these animals deserved consideration, shouldn't it also be illegal to throw a live lobster into a pot of boiling water?
Doesn't it makes you wonder? Over the years, what change? Why do people started to care about animals? What else do you have in mind about this paragraph?