Victor Frankenstein is a passionate scientist, but he lacks foresight and emotional connections. He is obsessed with the pursuit of his scientific achievements, and ignores the needs and desires of others. His genius is undeniable, but it is not held in check by any sense of morality or ethics. Victor believes that he is justified in committing acts vilified by society, such as grave-robbing and vivisection, in order to further the knowledge of the human life.
My temper was sometimes violent, and my passions vehement... It was the secrets of heaven and earth that I desired to learn... my inquiries were directed to the metaphysical, or in its highest sense, the physical secrets of the world.
(Shelley, Frankenstein, gutenberg.org)
Victor is also a coward; he is terrified of discovery, and so commits his sins in secret. He puts others in danger by hiding his actions, and instead of taking responsibility for his creation, he runs away. When he finally tries to make amends, it is far too late; his refusal to rake personal responsibility results in several deaths, including that of his beloved Elizabeth, by the Monster's hand.