Seeing as how Rand founded her ethics on an inquiry into value, basically assuming on the part of living beings that they "act to gain and/or keep" ends as part of their nature, I think her account of value could best be restated if it was founded on the Austrian school's axiom of action. I also think that it's necessary to stop regurgitating phrases such as "man's life qua man", "life makes value possible", "there is only one fundamental alternative in the universe: existence or non-existence", etc. For me and for some others I know, their meanings were fuzzy and they prohibited the understanding of what is actually a profound and intuitive argument that no one could rationally deny. (I found that, like F. A. Hayek, I couldn't make "heads nor tails" of Galt's speech the first few times I read it -- until I read Rasmussen's paper, "A Groundwork for Rights" and Tara Smith's Viable Values.) In other words, I believe the argument for life as the ultimate value could be reinterpreted so as to be stated in much clearer terms. The idea of a "premoral choice to live" I also believe is best rejected in favour of Rasmussen and Den Uyl's notion of a natural end that you are always affirming, every time you act: Living beings engage in goal-directed action, pursuing “values” that they “act to gain and/or keep”. This is known as the “action axiom”. Any attempt to deny that living beings act purposefully would itself constitute purposeful action, hence self-refuting. Action is distinguished from unconscious, involuntary responses to physical stimuli. A person asleep or in a coma obviously does not act. But the proposition is that living being acts, i.e. that one of its distinguishing features is conscious, self-directed (or “self-generated”, as Rand termed it) behaviour -- not that it always acts. At the bottom of every decision to engage in a particular action is the decision to engage in any action whatsoever: the, as it were, decision to make decisions. In order to act at all, a living being must evaluate that it would be preferable to be an acting, choosing entity than a non-acting, non-choosing entity. No decision and evaluations can be made without reference to a standard, a parameter one is intending to maximize. Since most ends are merely means to other ends, there must be an end-in-itself, an ultimate standard or, in Rand’s words, “ultimate value” to prevent an infinite regress. Ultimate value gives rise to the phenomenon of choice (i.e. action), by providing a living being with the capacity to reject alternative states of affairs as suboptimal. The decision to act is the decision that existence (life) is preferable to non-existence (death), because life requires, not only particular actions and particular values, but action and valuein themselves. A living being engaged in goal-directed action must therefore have life as its ultimate value. At the most fundamental level, it has decided to maximize this parameter by fulfilling its basic requirement: engaging in action. Consequently, at all other levels, no matter the content of the action (decisions about content also constituting action), life remains the ultimate standard throughout, because without it there could be no evaluation of action as preferable to non-action in the first place. Any attempt to deny that action has life as its ultimate standard qua value would constitute an action affirming life as its ultimate standard qua value: like the action axiom, also self-contradictory and self-refuting. Unlike other ends, life is an end-in-itself, because it is a means to itself. “Life is a process of self-sustaining and self-generated action”; i.e. it is composed of action (good or bad) that takes the shape of a structural, cyclical chain. Goal-directed action requires life qua ultimate value. Life qua ultimate value requires goal-direction action, which itself requires life qua ultimate value. Et cetera. (Conscious living beings cannot avoid engaging in action since the decision not to act would itself be an action.) Obviously, "life" just refers to survival, which Irfan Khawaja helpfully defined in an essay in "Metaethics, Egoism, and Virtue" as the promotion of optimal conditions for the operation of your essence across your natural lifespan. Yet Smith makes clear that the requirements of survival are long-range as well as short-range. Survival includes psychological as wellas physical health. In order to pursue sustenance, human beings must first be convinced their life is worth sustaining. For example, a person who pursues passions, fruitful relationships, hobbies, and a life of self-esteem clearly has better survival prospects than someone who is antisocial and suffers recurring bouts of mania and psychological depression. Human beings must therefore not only eat and have a pulse, but must objectively flourish: live in such a way as to be able to continueto live. We need happiness and self-esteem in the same way a plant needs water. Flourishing is thus, in keeping with the Aristotelian-scholastic moral tradition in which Randian ethics can be confidently categorized, man’s natural end: the summum bonum or ultimate good. I think the argument for moral principles can be stated like this: Goal A could be best achieved by doing X, Y, and Z. You want to achieve Goal A. Therefore, you should do X, Y, and Z. Goal A is your natural end, an "ought" you implicitly accept every time you act. Ergo, asking why you ought to obey moral principles is like asking why you should train for a 100-m sprint. Why run in that case? How can you win without training? As Khawaja wrote in the appendix to his review of Viable Values: "In choosing to live, one is conditionally bound by the requirements of life [...] if I will life as an end, I must will the means to it; if I refuse to will the means, I must give up the end." Your natural end cannot be rejected (unless you somehow completely shut down and stop acting). Hence, moral principles are obligatory.