The dichotomy, in briefest essence, hinges on what is contained in the
recognition of the normative reality of other humans beings.  Tara
Smith already exposes some of the floating deontology that goes on in
the Kantian tradition, in her -Moral Rights and Political Freedom-, but
let me give you the gist: Kantian floating deontologists take the
reality of other human beings with free will and free agency as having,
*on its own*, crucial moral import.  It would be a failure of practical
rational recognition not to recognize that other human beings are not
just a physical resource like anything else.  From this there is a
highly *intuitive*-driven argument that, because of others' moral
reality, one should not exploit them as one would any other natural
resource.

Supposedly from the fact, alone, of other human beings' being free
agents, derives the alleged "ought" that one should respect them.  Not
recognizing the moral reality of others is presumed to be a moral
failing of egoism, since egoism on the traditional interpretations has
it that the self is the only important repository of value, and others
are merely instrumental to my ends.  So Kant's project consists in
opposing this "egoist" and instill in folks a respect for the moral
law, which is not of instrumental value in its own right.  The problem
with the egoist?  Presumably, it's that egoistic moral prescriptions
are not universalizable.  Presumably, it's that the egoist sees things
in terms of "the only good is what serves my interests."  From the
alleged egoistic moral standpoint, others are reduced merely to means
to this end.

(This is by no means a made-up characterization of standard
interpretations, either.  It's well-stated in such places as Michael
Huemer's webbed "Why I Am Not an Objectivist" essay, just for a
starter.)

So we get Jim Prescott coming along and saying something to this effect
as well.  As he puts it: others are means to my ends.  He calls this a
proper Objectivist interpretation of egoism, even though the text of
Rand's argument explicitly rejects this notion.

Now, there is one un-controversial sense that all moral theorists seem
to agree on, and that is that treating others as means to one's ends is
permissible; it's treating others *merely* as means to our ends, just
like any other natural resource open for exploitation, that's usually
considered wrong.

Now, I do give Prescott the benefit of the doubt that he does recognize
the moral reality of others as beings just like him, as free and
end-directed agents.  But he also happens to view others as instruments
to his well-being, and I'm going to be more bold here and say that he
regards others as *mere* instruments to his ends.  That's what a coldly
rational egoist in his view takes in regard to his attitude to others.
No Kantian-deontological sentiment to cloud his perspective.  Now, he
*does* also take a *correct* tack in acknowledging, first, that egoism
*does*, contrary to standard interpretations, provide universal
prescriptions, and he also *does* correctly acknowledge that others'
being free agents by itself doesn't command his respect.  But what
*does* command his respect?  It's how the behaviors of others in
response to his behaviors can be strategically calculated so as to
produce what's best for himself.  And so it's this strategic response
and what falls out of it -- namely, contractual exchange -- and not the
fact of others being free agents, that gives rise to all involved
parties having rights.

What is absolutely clear, though, is that Rand's position is neither
the floating Kantian one, *nor* the Prescottian one.  It is the *fact*
of what human beings are, and the *recoginition* of the conditions of
existence required by man's life qua man, coupled with the moral
*purpose* of each person's life being the achievement of his own
happiness, that gives rise to the fully context-informed,
rationally-grounded principle that every man is an end in himself.  It
is in virtue of a man being an end in himself on *this* understanding,
that man has a *right* to exist for his own sake.

That's straightforward Randianism, without any unnecessary
complications, and it's a fully-grounded basis for our having rights.
These rights are *pre-contractual*.  We have them in virtue of the
conditions of existence required of our life as human beings, with our
own happiness as our highest moral purpose.  This is not some flight of
fancy or floating sentiment that Prescott's ridiculous straw-men keep
insinuating about "natural rights" theories.  There is no room here for
having to bargain for one's rights to be *left alone.*  Such would run
totally contrary to Rand's argument as explained and illustrated
throughout her works, fiction and non-fiction.  We have a right *to
exist for our own sake*, not a right to exist as long as it's for Jim
Prescott's sake.  There is one obligation with respect to others
required of Jim Prescott, given the requirements of man's life qua man:
to *leave alone* others who haven't entered into any agreement with
him.  That's not an "unchosen" obligation, but rather an obligation
based on one's conscious, rational recognition of the facts of reality.
 (One truly incapable of consciously and rationally recognizing such
falls, at best, into a class of beings designated "insane.")

As John Galt puts this whole matter:

"Do you ask what moral obligation I owe to my fellow men?  None --
except the obligation I owe to myself, to material objects, and to all
of existence: rationality.  I deal with men as my nature and theirs
demands: by means of reason.  I seek or desire nothing from them except
such relations as they care to enter of their own voluntary choice.  It
is only with their mind that I can deal and only for my own
self-interest, when they see that their interest coincides with theirs.
 When they don't, I enter no relationship; I let dissenters go their
way and I do not swerve from mine.  I win by means of nothing but logic
and surrender to nothing but logic.  I do not surrender my reason or
deal with men who surrender theirs."
(From the -Lexicon-, p. 449.)

Galt lets dissenters go their own way, just as he goes his own.  Why?
Because he recognizes in them the *right* to go their own way.  Just as
he wouldn't regard himself going his own way as a right-less creature
just because he and the dissenters didn't enter into contract.