It is not implausible to presume that the idea for the establishment of the Academy in 387 B.C. could have resulted from Plato's conviction that insofar as society could not ultimately conform to his own standards, the least he could do was to set up a small-scale copy of the ideal city within the city of Athens.
The Academy was an innovative institution. Its foundation and permanence signals a turning point in the history of ancient Greek philosophy. It should be thought up as an exclusive group of like-minded people, who decided to share a life devoted to philosophy and scientific knowledge. It was, in a way, the first university in the antiquity; a private school of philosophy structured hierarchically with a scholarch on the top rank, with expert researchers, teachers and students, permanent and probationary members. The link that tied them together was their cognitive goal: the investigation of truth. And on the grounds that, for Plato, knowledge gained its value only by helping people with their moral improvement, the Academy promoted the common way of life, the shared research, and the constructive dialogue.
The Academy attracted the most ingenious minds of the 4th century: the mathematician Theaetetus, the astronomers Eudoxus, Callipus and Heraclides, the philosophers Speusippus, Xenocrates, Philip of Opus, and of course Aristotle who devoted 20 years of his life in the Academy. Plato's vitality was invested in the creative environment of the Academy until his death in 347 B.C. Taking into account his preference for oral exchange, we presume that most of his activity in the Academy was directed in teaching and edifying his students. Ii is also presumable that the sum of Plato's mature dialogues must have been conceived, studied and discussed in the Academy.