I was asked for an explanation of what I mean by “arbitrary,” so I’ll make the distinction again below. I’ve also touched on this distinction in The problems of society, The roots of oppression, and Is electricity a non-arbitrary need?
Here’s another quick explanation:
When we confront and answer the normative question (what should we do?) we make a value judgment about what’s worth doing. To put it another way, we judge what end is good enough to be worth our time. Some of those judgments are arbitrary, some of them are non-arbitrary. Non-arbitrary value judgments are rooted in human ontology, which, to me, means that if the good you decide to pursue is necessary to survive or to fulfill a biological precondition, then the value of that good is non-arbitrary. An “arbitrary” value judgment, on the other hand, is made when the value of a good you decide to pursue is nonessential to survival or fulfilling biological precondition. “Arbitrary” is a sort of catch-all for values that don’t pertain to necessity — an “everything other than, until proven otherwise” set. For example, the judgment that decorating is good and the subsequent decision to decorate in a particular way are arbitrary. You would be perfectly fine if you did otherwise, so decorating is arbitrarily valuable. If you could prove that decorating in a particular way is ontologically necessary, then perhaps it could be considered non-arbitrary, but I think decorating is a good example because it’s so heavily based on personal preference. On the other hand, the judgment that eating is good and the subsequent decision to eat are non-arbitrary. Eventually you’ll die if you decide otherwise, so eating is non-arbitrarily valuable. I would also argue that the life-enabling environmental conditions of the Earth are non-arbitrarily valuable.
JMK
tothesungod 
A colleague of mine, Nick, from Bard CEP raised these points on Facebook, to which I responded — I think it’s worth re-posting here:
Nick: Thanks for the additional explanation. I’m not sure if I agree/follow with the reasoning in the original post re: Is electricity a non-arbitrary need? You claim that sex is a non-arbitrary need because, even though an individual can live without sex, the human species would end without it. From that I assume you are discussing non-arbitrary needs as they apply to the species and not the individual. If that is the case, then electricity is an arbitrary need since, as you admit, many individuals can and do get along with out it. In the absence of electricity millions of /individuals/ would perish, but not the species as a whole.
JMK: I suppose there does seem to be an inconsistency there, but I think the millions (maybe billions?) who would die without electricity are cause enough to graduate electricity from arbitrary to non-arbitrary when considering how to ethically prioritize what we focus on re: development, sustainable development, reducing poverty, global and environmental justice, etc. Perhaps the remark about sex should be a footnote, though, because it does seem like an exception. Food, drink, shelter, sleep and environmental conditions, are non-arbitrary on the individual and the species level, whereas sex is only non-arbitrary at the species level. Electricity may be another kind of exception; it’s non-arbitrary for some individuals, and then arbitrary for other individuals. Insofar as electricity is non-arbitrary for the species, I suppose we would have to decide how many people being non-arbitrarily dependent on electricity it would take for it to count as non-arbitrary at the species level. So whatcha think, 51%? 2/3s? According to http://www.globalissues.org, 1/4 of the world’s population lives without electricity. I wonder how many of the 3/4 of the human population that lives with electricity could survive without it.