“Life or death is man’s only fundamental alternative. To live is his basic act of choice. If he chooses to live, a rational ethics will tell him what principles of action are required to implement his choice. If he does not choose to live, nature will take its course.” — Ayn Rand
The highest value (which determines the hierarchy of one’s other values) is one’s own life.
This is because the fundamental alternative a human being faces is existence or non-existence: life or death.
If one wishes to live, one must choose to take those actions to obtain the values necessary to sustain one’s existence. Without life, all other values are illusory. It is the fact that one is alive, that makes the need for values possible.
[Top quote] Ayn Rand “Causality Versus Duty” Philosophy: Who Needs It 99