in what ways might the novella be a reflection of or a commentary on the scientific and social/ethical theories of its general time period (particulary Freud's theory of personality and social Darwinism)?

Hi, this is a pretty extensive question for this space. A proper answer to this would take much time and be too large for this space. Still, as this is a thematic question, many of your answers can be found at the GradeSaver theme page.

http://www.gradesaver.com/dr-jekyll-and-mr-hyde/study-guide/major-themes/