All of Book I is introductory or gives foundations, and Aristotle starts with an assumption to the effect that "the good is that at which all things aim", and about ends and means and their distinction.
 EVERY art and every inquiry, and similarly every action and pursuit, is thought to aim at some good; and for this reason the good has rightly been declared to be that at which all things aim.
This is Aristotle's starting assumption, that is very much in line with his general teleological presumptions. I will not discuss it, and merely note the following provisional assumptions I shall make, that are much more specific:
A1. The deliberate actions of human beings have ends (goals, aims).
A2. These ends are chosen (selected, acted upon) by the actors.
A3. Ends are chosen because the actor prefers them.
This is much less general than what Aristotle presumes, and it requires a few remarks and clarifications.
In A1 I restrict myself to human beings, and leave aside other things, whether animals, plants or inanimate nature. The main reason for this is to avoid complications.
Also, I am speaking specifically about deliberate actions, and not about reflexes, automatisms, habits, movements etc. (But it may be well to presume that what is called a human action is deliberate, or else should be called otherwise.)
In A2 I suppose something like free will. This may be an illusion (though I don't think so), but even so the point of ethics and morals is that it is supposed conscious deliberations and advice are somehow relevant to the ends one selects. For without a presumption like this all of it would be as useless as is preaching to a stone.
In A3 what I assume involves that the actor prefers the existence of the end over its non-existence. This in turn presumes that the actor can and does order the alternatives he or she considers and selects from somehow in some order of rank, on a scale of better and worse, and regardless of other possible properties of the scale, such as numerical values.
What these assumptions, like Aristotle's, leave open is what ends are. Since I have limited myself to human beings, I can propose the following provisional definition:
D1. An end of a person is a state of affairs or event that the person believes he can help to realize or maintain by his actions and desires to realize or maintain.
It is noteworthy that an end (1) depends on a person (2) involves beliefs of the person about the relevant facts (3) involves a desire on the part of the person and (4) usually, namely to the extent other persons are or may be involved, depends on the actions (and non-actions) of others.
Hence, ends are relative in these four senses - which does not mean they are necessarily relative or arbitrary in another sense, for many ends are not so much given as imposed, in as much as they depend on natural needs or social pressures a person cannot avoid.
There is the general question, or questions, concerning the relativity of ends, and of what's considered good, bad, right, wrong, and indeed other evaluating terms: Are judgments of value completely and only subjective, or is there an objective part or side to them?
At present I want to mostly avoid answering that question, except by noting that many human desires arise from human needs, that exist as a matter of fact, and that also it is fairly to very obvious in many contexts what are and are not factual means to obtain or further desired ends. So in these two senses, at least, there are objective facts involved in most judgments of value.
It makes sense to contrast wishes, desires and values, more or less on the following lines: A wish is a feeling one wants something; a desire is a feeling that something will further one's interests. And as it may very well be that what one thinks is in one's interests differs from what would currently be the most pleasant thing to do, it makes sense to distinguish between wishes and desires. Values are the personal judgments that are the basis of desires: Appraisals of what one considers morally good, ethically good, or personally pleasant.
And it is or should be clear that the ends of human beings are relative to many things, including their circumstances, knowledge, beliefs, character and courage. Even so, this does not mean at all that all values, all desires, all wishes are merely relative, or bound to be culturally relative nor does it mean that values, desires or even wishes cannot be based on realistic, informed and shrewed judgments of one's conditions and fellow-men. (See Edwards)
Besides, it is important to realize that most judgments about human beings in general or in groups are based on some presumptions about a human nature they all share, due to their similar anatomy and DNA, that give them many similar capacities, needs, and feelings in given situations.
And that various religions and political ideologies have differed considerably about what human nature is, this does not show at all there is no such thing as human nature, but only that it is difficult to circumscribe or define fully and precise
and as it happens some 95 KB of this file mysteriously disappeared over the summer of 2009, and my only copy is on a scratched disk.
So.... (1) people who have a complete copy: Please send it to me so that I can put it here again, and (2) I think it was a very good and original set of notes, and so I say to you if you stole it for your own Ph.D. or whatever (this is the first time a file has disappeared in this way for me): Shame on you!