'The word “mature” is defined as “complete in natural growth or development,” also “fully developed in mind and body.” Left undefined is the standard for development.
Without here delving into the full philosophical proof, let us accept for the sake of argument that human maturity is the capacity to deal rationally with the facts of reality and to act to sustain your life and pursue long-term happiness. Consider, the reason children remain in the care of parents until they reach adulthood is because they lack the knowledge and experience to act rationally in pursuit of their own lives. Otherwise, they would have no need of parenting.
An animal is mature at a certain age, having developed to the point where its instincts and physical abilities are sufficient for it to act according to its nature without the aid of its mother. Human beings are different. We alone must utilize reason in order to survive.
By this standard, it is apparent to the casual observer that maturity is a rare trait among men and women. Physical development is completely disconnected from the ability to deal rationally with the facts of reality. Indeed, many make it into middle and advanced age without maturing in this sense. Some go their entire lives without truly growing up...
It is bad enough when an individual refuses to mature. Consider the consequences of an entire nation intent on fantasy. Mark Steyn highlights the fact that President Obama’s currently proposed budget places the national debt on track to reach 900% of GDP by 2075. Are there any grown-ups among us prepared to deal with this reality?
The capacity of Americans to mature will determine whether or not we pull out of our cultural and economic nosedive and restore a republic governed by just laws which protect individual rights. It is the choice and capacity to acknowledge the requirements of life, to concede such axioms as “money doesn’t grow on trees,” which enable mature adults to act productively in pursuit of their own happiness. Absent that, misery is inevitable.'
- Helen Smith, 'American Immaturity: How We Grow Up After We Grow Old.'