The idealist, by definition, overestimates what is possible.

理想主义者的定义，是指高估某些可能的人。

youdao

The idealist declares that all is mind or energy, and that matter is necessarily unreal.

而唯心主义者则宣称世上所有的思想、能量和物质都是虚构出来的。

youdao

A long-haired, guitar-playing idealist who sings about bringing the world together.

VOA: special.2009.07.27

Premise 2: To be a practical idealist, the foundation of it has to be the belief that change is possible.

第二前提：,作为一个实际的理想主义者，它的基础必须是,相信改变是可能的。

哈佛公开课 - 幸福课课程节选

A long-haired,guitar-playing idealist who sings about bringing the world together.

VOA: special.2011.06.27

The idealist Rienzi, tribune of the people, reaches out to the predatory nobles.

WSJ: Richard Wagner's 'Orphans' | By Matthew Gurewitsch

The idealist is Sachs, whose 2005 The End of Poverty prescribes more aid.

FORBES: Wealth and Poverty

The leader has to be practical and a realist yet must talk the language of the visionary and the idealist.

FORBES: 100 Best Quotes on Leadership