There are a number of conceptual approaches to the issue of cruelty to animals.
For example, the animal welfare position holds that there is nothing inherently wrong with using animals for human purposes, such as food, clothing, entertainment, fun and research, but that it should be done in a way that minimizes unnecessary pain and suffering, sometimes referred to as "humane" treatment.
Animal rights theorists criticize these positions, arguing that the words "unnecessary" and "humane" are subject to widely differing interpretations, and that animals have basic rights.
They say that the only way to ensure protection for animals is to end their status as property and to ensure that they are never used as a substance or as a non-living thing.
The industrial nature of these facilities means that many routine procedures or animal husbandry practices impinge on the welfare of the animals and could arguably be considered as "cruelty", with Henry Stephen Salt claiming in 1899 that "it is impossible to transport and slaughter vast numbers of large and highly-sensitive animals in a really humane manner".
It has been suggested the number of animals hunted, kept as companions, used in laboratories, reared for the fur industry, raced, and used in zoos and circuses, is insignificant compared to farm animals, and therefore the "animal welfare issue" is numerically reducible to the "farm animal welfare issue".
Divergent approaches to laws concerning animal cruelty occur in different jurisdictions throughout the world.
For example, some laws govern methods of killing animals for food, clothing, or other products, and other laws concern the keeping of animals for entertainment, education, research, or pets.
Later, in The Descent of Man (1871), he wrote: "There is no fundamental difference between man and the higher mammals in their mental faculties." Animal cruelty can be broken down into two main categories: active and passive.
Passive cruelty is typified by cases of neglect, in which the cruelty is a lack of action rather than the action itself.