1 John Stuart Mill, Utilitarianism (1861) chapter 2, paragraph 2.
2 This, of course, is not in general true. Many people, apparently, find interest in the pictures and designs on stamps. Some people also care about the message that the stamp is sending to the recipient. (Consider the popularity of "Love" stamps.) But for the purposes of the example in the text imagine that all stamps are as ugly as metered mail but they lack the location information or other redeeming features.
3 I know of no one else who uses these terms to draw this distinction between kinds of consequentialist ethical theory.
4 We may distinguish self-conscious beings from the larger class of conscious (or sentient) being. Self- conscious beings are beings who are not only aware, but are aware of themselves as beings who exist in time. An animal may be sentient without being self-conscious.
5 No, I do not know whether bugs are sentient. There are serious epistemological questions concerning how we could know whether other beings (even other human beings, for that matter) are really sentient. While such questions make any sentience version of consequentialism hard to apply, I will pass over such practical difficulties here.
6 Perhaps the first was W.D. Ross. See The Right and the Good (Hackett, 1988--originally published 1930) chapter II, p.19.
7 Still, theories that consider effects to these beings as relevant I will call "sentience theories" by courtesy.
8 Please understand that I am not implying that utilitarianism is the correct ethical theory.
9 Mill states his theory in terms of happiness, but says "by happiness is intended [i.e. is meant] pleasure and absence of pain." Utilitarianism chapter 2.
10 Curiously, John Stuart Mill, paradigmatically regarded as a mainstream utilitarian, says in a footnote (Utilitarianism (2nd edition and beyond) chapter 2) that what counts is the intention, and indeed it is the intention that determines what the action is.
11 It has also been expressed (by utilitarian J.J.C. Smart) as a distinction between extreme and restricted utilitarianism.
12 It would be easier to say "which are right and which are wrong," but "right" here is ambiguous between "morally required" and "morally permissible." It is morally "right" to wear the color green? Well, it is not wrong, but neither is it wrong not to do it. Still, sometimes for ease of expression I speak more simply of "right" and "wrong."
13 A Theory of Justice (Belknap Press, 1971) §5, p.27.