Mary Shelley wasn’t just brilliant, of course, she was also perceptive, and understood lots about creativity and art.
Every thing must have a beginning, to speak in Sanchean1 phrase; and that beginning must be linked to something that went before […] Invention, it must be humbly admitted, does not consist in creating out of void, but out of chaos; the materials must, in the first place, be afforded: it can give form to dark, shapeless substances, but cannot bring into being the substance itself. In all matters of discovery and invention, even of those that appertain to the imagination, we are continually reminded of the story of Columbus and his egg. Invention consists in the capacity of seizing on the capabilities of a subject, and in the power of moulding and fashioning ideas suggested to it.
— Mary Shelley