However and Whereas: 然而 and 而

The idea: a turn, or a comparison?

Both words contain 而 (and yet), but they do different jobs. 然而 is 然 (so) + 而: 'it was so, and yet…', so it turns against the expectation the previous sentence built, and it heads a new sentence. 而 alone sets two parallel facts side by side inside one sentence, right before the second subject.