Victor Frankenstein did make the monster out of the fascination of life and death. Growing up in Geneva, he read works of the outdated and ancient alchemist, which doesn’t serve him any purpose while he attended Ingolstadt University later on. In this university, he took up modern science and masters them all within a few years, even more than what the professors could teach. With that skill equipped, he became engrossed with the idea of “secret of life” and discovered it, bringing the monster to life.
He slowly transformed over the course of the story, from an innocent young man that is amazed by what science could bring, into an arrogant, delusional man. It could be from the desire to obtain a power that rivaling that of the God, to create a new life, an endeavor that is shunned by the rest of the scientists. He also saw M. Krempe, a natural philosopher that Victor met in Ingolstadt, as a model scientist. To him, science is a mystery for all to probe, but once its secrets are discovered, it must then be guarded. So then he created the monster just to prove himself.