The significance of this quote lies in the way that it helps us to see and understand more of Victor's background prior to his decision to forge ahead and create the creature that represents such a breakthrough of scientific knowledge. What is particularly interesting about this quote is that it deliberately alludes to the way in which Victor's father tried to protect his son from any "supernatural horrors" or psychological burdens. Yet, in retrospect, we cannot help but think that if Victor had experienced any of these "supernatural horrors" he might have been less willing to go ahead and create a new life form with such shocking consequences.
It is precisely the fact that Victor has been protected from any "supernatural horrors" that arguably prevents him from thinking through the consequences of his actions and likewise renders him so horror-struck with his creation after he has given it life. His father, through trying to protect his son and to bring him up as a rational man, actually sows the seeds of his son's future failure and downfall as he is unable to prevent himself from firstly creating his creature and then secondly to stop himself being repelled by what he has created.