The Objectivist ethics holds man’s life as the standard of value — and his own life as the ethical purpose of every individual man.
The difference between “standard” and “purpose” in this context is as follows: a “standard” is an abstract principle that serves as a measurement or gauge to guide a man’s choices in the achievement of a concrete, specific purpose. “That which is required for the survival of man qua man” is an abstract principle that applies to every individual man. The task of applying this principle to a concrete, specific purpose — the purpose of living a life proper to a rational being — belongs to every individual man, and the life he has to live is his own.
Man must choose his actions, values and goals by the standard of that which is proper to man — in order to achieve, maintain, fulfill and enjoy that ultimate value, that end in itself, which is his own life.
The standard of value of the Objectivist ethics — the standard by which one judges what is good or evil — is man’s life, or: that which is required for man’s survival qua man.
Since reason is man’s basic means of survival, that which is proper to the life of a rational being is the good; that which negates, opposes or destroys it is the evil.