Gilbert Meilaender on when curiosity can be vicious

Many possibilities may pique my curiosity — I may wonder how … human beings respond to experiments harmful to their bodies, or even to suffering; how the development of a fertilized egg could be stimulated to produce a monster rather than a normal human being; how to preserve a human being alive forever. I may wonder, but it would be wrong to seek to know. Not, in every case, because I cannot know, but because I cannot possess such knowledge while willing what is good. … To love the good and to possess what we love are, in this life, not always compatible. Hence, to seek always to love the good is to commit ourselves to a life that seeks to receive, not to possess.

Although Augustine does not outline for us any general principle by which we can always distinguish a proper desire for knowledge from the vice of curiosity, we can learn from him the attitude which may at least make virtue possible — an attitude characterized by a reverent desire to understand creation rather than a longing to possess the experience of knowing.

from The Theory and Practice of Virtue (Univ. Notre Dame Pr., 1984), 140.