How, then, do we determine what is needed for survival?
It is easy to see how by the standard of life, for example, drinking water can be judged as good, and walking into the path of a speeding car can be judged as bad. But Rand's ethics, of course, contains much more than that; there are many principles and virtues in Rand's ethics that are not so directly related to survival. The central argument which neo-Aristotelians, such as Douglass Rasmussen and Douglass Den Uyl [2], and Roderick Long [3], use against survival as the standard, is that on the standard of survival, productivity, non-initiation of force, the value of art, and many other virtues and values accepted by Objectivists, can't be justified.
The crucial point, in answer to this argument, is that life as the standard of value does not mean immediate survival as the only goal. As Leonard Peikoff explains: "A self-destroying action need not be immediately fatal. .... It is possible to deteriorate gradually for years, breathing all the while, but increasingly damaged." And our judgment, of actions causing such drawn-out destruction, as wrong, is still guided by the standard of survival. "The size and form of the damage are not relevant here. No threat to vitality --- no undermining of one's capacity to deal successfully with the environment --- can be countenanced if life is the standard of value. The reason is that no such threat can be inflicted safely on so complex and delicate an integration as a living organism." [4]
How do we identify actions which are self-destroying, which damage one's ability to survive, if they are not immediately fatal? And conversely, how do we identify actions which contribute to one's ability to survive, if their benefit is not immediate?
A living organism can be seen as a complex machine, aimed at its own survival. The role of its various organs and faculties can be understood analogously to understanding the parts of a machine.
For example, an automobile is designed for the purpose of travelling. Some of its parts --- e.g. the engine, or the steering-wheel --- contribute directly to this purpose. Other parts make only an indirect contribution; the cooling and lubrication systems, for example, do not directly help to move the automobile, but are necessary to maintain the engine's functioning; the engine's lid does not directly help to move the automobile, but contributes to this purpose by protecting the engine from rain, falling objects and other hazards [5].
Similarly, a living organism has many organs and faculties, all having evolved for the same ultimate goal: survival. Some of these faculties contribute directly to maintaining the organism's life. Others have a more indirect role, protecting the organism from external damage, or helping to maintain specific faculties which, in turn, maintain its life. In some cases, their role may not be obvious withour specific knowledge and thinking about the nature and environment of the organism (just as the role of the cooling system in an automobile will not be obvious without knowledge of the engine's operation and of the effects of high temperatures on its materials). To understand the value-significance of an organ or faculty in an organism, we need to identify its contribution --- direct or indirect --- to the organism's survival [6].
As an example, consider the lion's mane. The mane does not do anything directly to maintain the lion's life, and it might seem, at first glance, that it does not have such a role at all. It is therefore tempting, in analysing the role of a lion's mane, to adopt the analog of the flourishing standard, and conclude that having a mane is not needed for survival, but is part of the lion's "good life"; if a lion were to lose its mane, or be born with a small mane, that would not be destructive to its survival, but would make its life less full, less flourishing, or less leonine. Further study, however, proves that the mane does have an important role in the lion's survival. The lion's conditions of living are such that it often gets into fights with other lions; it is common, in such fights, for the lion to receive blows to the head. The mane, by deflecting and cushioning such blows, can prevent them from wounding, or even killing, the lion. It is this value-significance of the mane which originally caused its evolution. If a lion were to lose its mane, that would not be immediately fatal; in some cases, it might even end up never bringing about the lion's death, since the lion might happen to live the rest of its life never receiving any blows to the head. Still, such an event should be regarded as destructive for the lion, because of the mane's potential role protecting the lion's survival. [7]