All English transition words and phrases sometimes also called 'conjunctive adverbs' do the same work as coordinating conjunctions: they connect two words, phrases or clauses together and thus the text is easier to read and the coherence is improved.
If we forget that humans are capable of such ugliness and terror we are doomed to repeat these evils. Hence, many historians view that American policy of isolationism as one of the passive enabling forces of the Holocaust.
If it still sounds correct it probably is. It shows the loneliness inherent within a big city. First, it shows the loneliness inherent within a big city. Consequently, she failed freshman English. This was no small service that religion provided as often the severity of their circumstances in the new world warranted such mental cushioning.