He is a pessimist and a defeatist.

他是悲观主义者，也是失败主义者。

《牛津词典》

Be neither a pessimist nor an optimist, but a leader.

做生活的领导者，而不是悲观者或乐观者。

youdao

There is a famous old story about an optimist and a pessimist.

有一个关于一个乐观者和一个悲观者的著名而古老的故事。

youdao

"I'm an optimist, and I think if you're a pessimist that's just an excuse for inaction."

VOA: standard.2010.02.24

Chaka said in our situation, it's a luxury to be a pessimist.

NPR: Israeli Director Deconstructs a Troubled House

A. Well, as I've had a lot of people tell me, I'm a pessimist, but also I--I wasn't prepared.

CNN: Transcripts from video deposition of Lewinsky, Jordan, and Blumenthal

If Freud were simply a pragmatic pessimist there is no way I would suggest giving him (actually, his ideas) a seat at your holiday table.

FORBES: Newtown Is Why You Should Bring Einstein And Freud To Your Holiday Gatherings