Plato's contribution" :
1-in his works appeal for the conception of mimeses or imitation as the essential characters of all arts. All arts are related in his sense for they all imitate nature.
2- Though Plato regard imitation as a mere copy of surface appearances, yet at places, he advances a little further. Such imitation, he associated with poetry of the highest kind which represented things as they ought to be and not in their actuality. Thus, we find hints of him of poetry being a creative process. He lays high standard for literary criticism. a critic must have courage, knowledge and wisdom . He must lead the many and be not led by them. States of the general public can not determine literary standards
4-He makes significant advance in his views of inspiration when he regards it as aesthetic power of a form of spiritual exultation which tends the soul a quest of ideal beauty. It liberates the soul from the bondage of custom and convention and carries man nearer to truth.
5- Poetry is an inspiration, but it is also an art and Plato breaks new ground in laying down basic principles for its practice as an art. The artist must take those . He must select and organize his material. a poet must have knowledge of the rules and techniques of his art . He must follow the law of order and restrains and study exercise and learning what is essential.