If you believe that an article, a letter, a motivational speaker, a talk show, or a self-help book, or even just a Google search for medical or diet information, can impart wisdom, advice, knowledge, or truth, then you are a practitioner of what the Greeks called the didactic.
This pretty much describes everyone. And it also describes the heart and roots of education. If you think that a textbook, lecture, study guide, or online course can transmit effective information, then you are practicing the didactic. Reading this blog is didactic.
Theologians describe some of the New Testament epistles, such as the Epistle of James, as didactic.
The didactic was a delivery method -- excuse me, is a delivery method.
The Greeks believed that beliefs could be transmitted verbally, visually, materially to others. Hence, architecture could communicate order and harmony by embodying the "perfect" repeated geometry of The Golden Ratio. This was important to them because the Greeks, like Buddhists, believed that the only good existence was one harmonious with nature.
The Greek temples were a delivery system -- Greeks believed that knowledge could be shared through speech, letters, plays, works of art, sculptures, and architecture. History as well as religion could be preserved that way, hence the Greek orders that captured their roots as Dorians and their debt to the influences of Ionia and the Orient.
The didactic method informed Early Christian and Medieval art. Complex theology, such as a theophany and "original sin", could be transmitted via imagery. Bible stories could be conveyed and called to remembrance through art.
Artists have therefore been informed theologians and philosophers throughout history. There are practical implications as well. Without thorough knowledge of physics your sculpture may not last, and without a keen awareness of chemistry you just might poison yourself. Without some political savvy you might be poisoning yourself as well -- or setting yourself up to be poisoned.
Know and respect your patrons.
The didactic is not only the bedrock of liberal arts, all teaching and textbooks operate via didactic methods, irregardless of discipline.
So, should art be part of the core of educational requirements? Well, art is a delivery system. It has always been and will always be. We all make choices. You can choose to be affiliated, such as iconography, or disaffiliated, such as graffiti, but you can't remove the human from humanity.
So, will we manage, own and learn through the delivery system? Or do we do something else?
All alphabetic letters began as pictures. Even if you take illustrations away, the words that you read began as pictures. Writing is actually drawing. Is art really necessary? Well, is the didactic necessary?