The concept of animal sanctity branches as far back as one can imagine. In ancient times animals were considered to have intelligence and even a language all of their own. This was an early view on animals stemming from pre-agrarian living which is commonly seen to have little significance in today's debate. Somewhere along the way animals lost their position of sentience and this is reflected in the arguments of Descartes that will be discussed later. In Descartes arguments he carefully denies animals the kind of intelligence that is attributable in most cases to human beings. Around this time the historical debate over animal sanctity lost its supposition that animals may have a degree of intelligence over human beings.
The debate was now placed for the question whether animals, being with or without intelligence, deserve a degree of rights, and if so what degree of rights do they deserve? This question is what Peter Singer grapples with today, and which I will discuss in the second part of this essay.
Descartes begins his argument about the soul by comparing the human body to machines and animals. Here he says that machines and animals both have something in common, as animals and humans have something also in common. Animals and humans on the one hand have what he terms the animal spirits' which control bodily organs, movements and involuntary actions. While animals and machines share that they may appear to be thinking but do not actually think. He writes that "if any such machines had the organs and outward shape of a monkey we should have no means of knowing that they did not possess entirely the same nature as animals." 1. (1)
So one is left here to make ones own...