What is the author's intent in this excerpt?

C. Portrays the free states metaphorically as a haven after shipwreck (shores, surges); describes the slaves' escape as the work of God (miraculous providence); excuses their ignorance and sometimes bad behavior, using words that imply illness (feeble, infirm) and blaming it on the "system" - that is, on slavery - which it condemns as unChristian and immoral.