Imagination is inner vision. It is in this way that blindness can be a gift. Through the imagination words are given life. They illuminate one's world so that even the blind would see. The blind is also not troubled by the present and the immediate, but only visualizes things through time.
The muse is the goddess of absolute memory.
The argument made and discussed about in this interview is that the Homeric epics — among others — are orally composed. It belonged to an oral tradition of performing poetry. The writing down happened much later, and the written work itself gained more significance than the oral act as time passed. How the great poems get canonized, Nagy argues, is through this evolution-like process of 'crystallization.'
Oral and written composition are different mediums. Written works are way more complex and hard to read than oral works, because written works do not need to be easily and quickly remembered — a demand for the oral medium.
Letters resurrect when you pick up the book and read it. The mummified Osiris comes back to life when his tales are read. The library of Alexandria was meant to serve as Alexander the Great's mummy — his path to immortalization. Every time people read his works, he comes back to life. Plato channels Socrates by invoking his dialogues. Even if Socrates dies, his dialogues must live on.