每日一词学英语(11): sanguine

先看下面这段话：
Yesterday’s late collapse by the London stock market raised fears that the market’s recent good run could be about to come to an abrupt end, but it’s a case of onwards and upwards this morning after a well-received trading update from Royal Bank of Scotland (RBS) and a sanguine response to yesterday’s US banking ‘stress tests’ which revealed that ten of the US's largest banks need to raise a further $74.6bn in capital towithstand the current recession.
伦敦证券市场收盘大跌，引发市场恐慌，不过美国银行业的“压力测试”结果很快又提振了乐观情绪。sanguine在这里的意思是cheerfully confident, optimistic。今天的重点是学习它表示“乐观”的用法，比如：a sanguine nature/disposition, be sanguine of, etc.。

Sanguine的字面意思是红色，就是达芬奇自画像的那种颜色(见上图)。在心理学上是四种气质(four temperament types)中的一种，热情奔放的多血质型。另外三种是胆汁型(Choleric)，抑郁型(Melancholic)和黏液型(Phlegmatic)。分别起源于中世纪生理学中的四种体液(four humors): blood, bile, black bile, phlegm。可能很多人都知道了，这里温习一下英文说法。