Etymology

The word "charity" entered the English language through the Old French word "charité" which was derived from the Latin "caritas".^[1]

Originally in Latin the word caritas meant preciousness, dearness, high price. From this, in Christian theology, caritas became the standard Latin translation for the Greek word agapē, meaning an unlimited loving-kindness to all others, such as the love of God. This much wider concept is the meaning of the word charity in the Christian triplet "faith, hope and charity", as used by the King James Version of the Bible in its translation of St Paul's Letter to the Corinthians. However the English word more generally used for this concept, both before and since (and by the "King James" Bible at other passages), is the more direct love. (See the article Charity (virtue))

St Paul's agapē was not primarily about good works and giving to the poor (And though I feed the poor with all my goods, and though I give my body, that I be burned, and have not love [agapē], it profiteth me nothing - 1 Cor 13:3, Geneva translation, 1560), although in English the word "charity" has steadily acquired this as its primary meaning, wherein it was first used in Old French at least since the year 1200 A.D..

Philanthropy is the act of donating money, goods, services, time and/or effort to support a socially beneficial cause, with a defined objective and with no financial or material reward to the donor. In a more general sense, philanthropy may encompass any altruistic activity intended to promote good or improve human quality of life. One who practices philanthropy may be called a philanthropist. Although such individuals are often rich, people may perform philanthropic acts without possessing great wealth.

Philanthropy is a major source of income for fine arts and performing arts, religious, and humanitarian causes, as well as educational institutions (see patronage). The greatest philanthropist of all time is considered to be Andrew Carnegie.

During the past few years, some high profile examples of philanthropy include Irish rock singer Bono's campaign to cancel Third World debt to developed nations; the Gates Foundation's massive resources and ambitions, such as its campaigns to eradicate malaria and river blindness; and billionaire investor and Berkshire Hathaway Chairman Warren Buffett's donation in 2006 of $31 billion to the Gates Foundation.

The cat (Felis catus), also known as the domestic cat or house cat to distinguish it from other felines and felids, is a small predatory carnivorous species of crepuscular mammal that is valued by humans for its companionship and its ability to hunt vermin, snakes, scorpions and other unwanted household pests. It has been associated with humans for at least 9,500 years.^[5]

A skilled predator, the cat is known to hunt over 1,000 species for food. It can be trained to obey simple commands. Individual cats have also been known to learn on their own to manipulate simple mechanisms, such as doorknobs. Cats use a variety of vocalizations and types of body language for communication, including meowing, purring, hissing, growling, squeaking, chirping, clicking, and grunting.^[6] Cats may be the most popular pet in the world, with over 600 million in homes all over the world.^[7] They are also bred and shown as registered pedigree pets. This hobby is known as the "cat fancy."

Until recently the cat was commonly believed to have been domesticated in ancient Egypt, where it was a cult animal.^[8] However a 2007 study found that the lines of descent of all house cats probably run through as few as five self-domesticating African Wildcats (Felis silvestris lybica) circa 8000 BC, in the Near East

Physiology

Size

Diagram of the general anatomy of a male cat

Cats typically weigh between 2.5 and 7 kg (5.5–16 pounds); however, some breeds, such as the Maine Coon, can exceed 11.3 kilograms (24.9 lb). Some have been known to reach up to 23 kilograms (51 lb) due to overfeeding. Conversely, very small cats (less than 1.8 kilograms (4.0 lb)) have been reported.^[9]

The largest cat ever was officially reported to have weighed in at about 21.297 kilograms (46.952 lb) (46 lb 15.25 oz).^[10][11] The smallest cat ever officially recorded weighed around 3 lbs (1.36 kg). ^[12]

Skeleton

Cats have 7 cervical vertebrae like almost all mammals, 13 thoracic vertebrae (humans have 12), 7 lumbar vertebrae (humans have 5), 3 sacral vertebrae like most mammals (humans have 5 because of their bipedal posture), and, except for Manx cats, 22 or 23 caudal vertebrae (humans have 3 to 5, fused into an internal coccyx). The extra lumbar and thoracic vertebrae account for the cat's enhanced spinal mobility and flexibility, compared with humans. The caudal vertebrae form the tail, used by the cat as a counterbalance to the body during quick movements. Cats also have free-floating clavicle bones, which allows them to pass their body through any space into which they can fit their heads.^[13]

Mouth

Cats have highly specialized teeth for the killing of prey and the tearing of meat. The premolar and first molar together compose the carnassial pair on each side of the mouth, which efficiently functions to shear meat like a pair of scissors. While this is present in canids, it is highly developed in felines. The cat's tongue has sharp spines, or papillae, useful for retaining and ripping flesh from a carcass. These papillae are small backward-facing hooks that contain keratin which also assist in their grooming.

As facilitated by their oral structure, cats use a variety of vocalizations and types of body language for communication, including meowing, purring, hissing, growling, squeaking, chirping, clicking, and grunting.^[6]

Ears

Thirty-two individual muscles in each ear allow for a manner of directional hearing:^[14] a cat can move each ear independently of the other. Because of this mobility, a cat can move its body in one direction and point its ears in another direction. Most cats have straight ears pointing upward. Unlike dogs, flap-eared breeds are extremely rare. (Scottish Folds are one such exceptional mutation.) When angry or frightened, a cat will lay back its ears, to accompany the growling or hissing sounds it makes. Cats also turn their ears back when they are playing, or to listen to a sound coming from behind them. The angle of cats' ears is an important clue to their mood.

Legs

Cats, like dogs, are digitigrades. They walk directly on their toes, with the bones of their feet making up the lower part of the visible leg. Cats are capable of walking very precisely, because like all felines they directly register; that is, they place each hind paw (almost) directly in the print of the corresponding forepaw, minimizing noise and visible tracks. This also provides sure footing for their hind paws when they navigate rough terrain.

Claws

Like nearly all members of family Felidae, cats have protractable claws. In their normal, relaxed position the claws are sheathed with the skin and fur around the toe pads. This keeps the claws sharp by preventing wear from contact with the ground and allows the silent stalking of prey. The claws on the forefeet are typically sharper than those on the hind feet.^[15] Cats can voluntarily extend their claws on one or more paws. They may extend their claws in hunting or self-defense, climbing, "kneading", or for extra traction on soft surfaces (bedspreads, thick rugs, etc.). It is also possible to make a cooperative cat extend its claws by carefully pressing both the top and bottom of the paw. The curved claws may become entangled in carpet or thick fabric, which may cause injury if the cat is unable to free itself.

Most cats have five claws on their front paws, and four or five on their rear paws. Because of an ancient mutation, however, domestic and feral cats are prone to polydactylyism, (particularly in the east coast of Canada and north east coast of the United States of America) and may have six or seven toes. The fifth front claw (the dewclaw) is proximal to the other claws. More proximally, there is a protrusion which appears to be a sixth "finger". This special feature of the front paws, on the inside of the wrists, is the carpal pad, also found on the paws of big cats and dogs. It has no function in normal walking, but is thought to be an anti-skidding device used while jumping.

Skin

Cats possess rather loose skin; this allows them to turn and confront a predator or another cat in a fight, even when it has a grip on them. This is also an advantage for veterinary purposes, as it simplifies injections.^[16] In fact, the lives of cats with kidney failure can sometimes be extended for years by the regular injection of large volumes of fluid subcutaneously, which serves as an alternative to dialysis.^[17][18]

The particularly loose skin at the back of the neck is known as the scruff, and is the area by which a mother cat grips her kittens to carry them. As a result, cats tend to become quiet and passive when gripped there. This behavior also extends into adulthood, when a male will grab the female by the scruff to immobilize her while he mounts, and to prevent her from running away as the mating process takes place.^[19]

This technique can be useful when attempting to treat or move an uncooperative cat. However, since an adult cat is heavier than a kitten, a pet cat should never be carried by the scruff, but should instead have its weight supported at the rump and hind legs, and at the chest and front paws. Often (much like a small child) a cat will lie with its head and front paws over a person's shoulder, and its back legs and rump supported under the person's arm.

Senses

The nose of a cat. The feline sense of smell is extremely sensitive.

Main article: Cat senses

Cat senses are attuned for hunting. Cats have highly advanced hearing, eyesight, taste, and touch receptors, making the cat extremely sensitive among mammals.^{[citation needed]}

Cats' night vision is superior to humans although their vision in daylight is inferior.^{[citation needed]} Cat eyes have a tapetum lucidum and cat eyes that are blue typically lack melanin and hence can show the red-eye effect (see odd-eyed cat).

Humans and cats have a similar range of hearing on the low end of the scale, but cats can hear much higher-pitched sounds, up to 64 kHz, which is 1.6 octaves above the range of a human, and even one octave above the range of a dog.^[20]

A domestic cat's sense of smell is about fourteen times as strong as a human's.^[21]

Due to a mutation in an early cat ancestor, one of two genes necessary to taste sweetness may have been lost by the cat family.^[22]

To aid with navigation and sensation, cats have dozens of movable vibrissae (whiskers) over their body, especially their face.

Metabolism

Two cats curled up together

Cats conserve energy by sleeping more than most animals, especially as they grow older. The daily duration of sleep varies, usually 12–16 hours, with 13–14 being the average. Some cats can sleep as much as 20 hours in a 24-hour period. The term cat nap refers to the cat's ability to fall asleep (lightly) for a brief period and has entered the English lexicon – someone who nods off for a few minutes is said to be "taking a cat nap".

Due to their crepuscular nature, cats are often known to enter a period of increased activity and playfulness during the evening and early morning, dubbed the "evening crazies", "night crazies", "elevenses" or "mad half-hour" by some.^[23][24]

The temperament of a cat can vary depending on the breed and socialization. Cats with oriental body types tend to be thinner and more active, while cats that have a cobby body type tend to be heavier and less active.

The normal body temperature of a cat is between 38 and 39 °C (101 and 102.2 °F).^[25] A cat is considered febrile (hyperthermic) if it has a temperature of 39.5 °C (103 °F) or greater, or hypothermic if less than 37.5 °C (100 °F). For comparison, humans have a normal temperature of approximately 36.8 °C (98.6 °F). A domestic cat's normal heart rate ranges from 140 to 220 beats per minute, and is largely dependent on how excited the cat is. For a cat at rest, the average heart rate should be between 150 and 180 bpm, about twice that of a human (average 80 bpm).