The word is used so loosely that to talk about "education" without qualifying adjectives attached to it is not informative; or worse, it is misleading.
The qualifying adjectives I suggest are "general" and "special," "preparatory" and "continuing," "terminal" and "unending." Most people think of education as something that goes on in educational institutions, schools, colleges, and universities. They regard persons who have earned a diploma, a certificate, or a degree as individuals who, to some extent, have been educated.
They forget that individuals learn a great deal with little or no schooling. They forget that experience teaches, and that learning by any means is part of a lifelong educational process. Schools of all grades and kinds are only one group of means in the pursuit of education.
A much better question to ask is: Who is a generally educated human being? The negative answer is easy; certainly not any person who has just earned a diploma: a degree, or some other sort of certification.
Youth itself is the greatest obstacle to becoming a generally educated human being. Schooling at its best is preparatory. In addition, it is often specialized, preparing individuals for some forms of skilled work or for professional expertise. Finally, it is terminal: it can be completed in a relatively few years.
When the school is liberal, when it trains individuals in the liberal arts that are the arts of learning, it is preparatory. Those who are liberally trained to read and write, speak and listen, measure and calculate, have acquired the skills to go on learning after they have graduated, but unless they continue to learn year after year, they are likely never to become generally educated human beings. If the liberal training they receive in school includes a taste of all the major disciplines they will have some awareness of what there is to learn in order to become generally educated by the end of their lives.
Becoming a generally educated person is a lifelong process. It is an unending pursuit of learning, concluded by death but never finished or terminated by death. In my judgement, sixty is the age at which one can begin to become generally educated, on condition, of course, that the process has been continuing after all schooling has been finished.
After age sixty, one is fully mature and experienced, has been challenged by all the intricate problems of living, has done a great deal of conversing, and is finally ready to make and defend solutions to life's major problems, or to acknowledge the existence of problems to which one can find no satisfactory solutions.
Individuals whose schooling was specialized rather than liberal and who do not continue learning when they leave schooling behind, or do so only to improve their specialized expertise, never become generally educated human beings. This statement holds for most physicians, lawyers, and engineers, as well as for most who getting a Ph.D. merely indicated the field of specialization they would cultivate thereafter.
Adler's Philosophical Dictionary (1995)
Great Ideas from the Great Books (1963)
by Mortimer J. Adler