Samuel Ullman 塞缪尔·乌尔曼 (1840年4月13日 - 1924年3月21日)，犹太人，美国作家，1840年生于德国，儿时随家人移居美国，参加过南北战争，之后定居英国伯明翰，经营五金杂货，年逾70岁开始写作。
他于78岁时写的散文《Youth》因麦克阿瑟将军的喜爱而出名。
以下是Samuel Ullman的《Youth》
Youth is not a time of life;
It is a state of mind;
It is not a matter of rosy cheeks, red lips and supple knees;
It is a matter of the will, a quality of the imagination, a vigor of the emotions; It is the freshness of the deep springs of life. Youth means a temperamental predominance of courage over timidity of the appetite, for adventure over the love of ease. This often exists in a man of sixty more than a boy of twenty. Nobody grows old merely by a number of years. We grow old by deserting our ideals. Years may wrinkle the skin, but to give up enthusiasm wrinkles the soul. Worry, fear, self-distrust bows the heart and turns the spirit back to dust. Whether sixty or sixteen, there is in every human being's heart the lure of wonder, the unfailing child-like appetite of what's next, and the joy of the game of living. In the center of your heart and my heart there is a wireless station; so long as it receives messages of beauty, hope, cheer, courage and power from men and from the infinite, so long are you young.
When the aerials are down, and your spirit is covered with snows of cynicism and the ice of pessimism, then you are grown old, even at twenty, but as long as your aerials are up, to catch the waves of optimism, there is hope you may die young at eighty. Note: This poem is better known in Japan because it was a favourite of General Douglas MacArthur who had a framed copy on his office wall in Tokyo during the Occupation of Japan and regularly quoted the poem in his speeches.
According to Margaret England Armbrester, a Japanese businessman by the name of Yoshio Okada read about MacArthur’s love of the poem in the December 1945 issue of Reader’s Digest. He found the poem very moving and translated it into Japanese to display in his own office.
青春不是年华，而是心境；青春不是桃面、丹唇、柔膝，而是深沉的意志，恢宏的想象，炙热的恋情；青春是生命的深泉在涌流。
青春气贯长虹，勇锐盖过怯弱，进取压倒苟安。如此锐气，二十后生而有之，六旬男子则更多见。年岁有加，并非垂老，理想丢弃，方堕暮年。
岁月悠悠，衰微只及肌肤；热忱抛却，颓废必致灵魂。忧烦，惶恐，丧失自信，定使心灵扭曲，意气如灰。
无论年届花甲，拟或二八芳龄，心中皆有生命之欢乐，奇迹之诱惑，孩童般天真久盛不衰。
人人心中皆有一台天线，只要你从天上人间接受美好、希望、欢乐、勇气和力量的信号，你就青春永驻，风华常存。
一旦天线下降，锐气便被冰雪覆盖，玩世不恭、自暴自弃油然而生，即使年方二十，实已垂垂老矣；然则只要树起天线，捕捉乐观信号，你就有望在八十高龄告别尘寰时仍觉年轻。
青春不是生命里的一段时光，不是指红润的脸颊、红扑扑的嘴唇和柔软的双膝；它是一种精神状态，是指不懈的干劲、丰富的想象力和滚烫的情怀。
它是生命春意正浓时鲜活的记忆,它是生命之源勃勃生机的涌泉；青春意味着战胜懦弱的那股大丈夫气慨和摒弃安逸的那种冒险精神。
往往一个60岁的老者比一个20岁的青年更多一点这种劲头。
人老不仅是岁月流逝所致，更主要的是懒惰不思进取的结果。
光阴可以在颜面上留下印记，而热情之火的熄灭则在心灵上刻下皱纹。
遗憾、恐惧、缺乏自信，会扭曲人的灵魂，并将青春化为灰烬。
无论60岁还是20岁，您需要保持永不衰竭的好奇心，永不熄灭的孩提般求知的渴望和追求事业成功的欢乐与热情。
在你我的心底，都有一座无线电台：它能在多长时间里，接收到人间万物传递来的美好、希望、欢乐、鼓励和力量的信息，您就会年轻多长时间。
当天线倒塌时，您的精神就被玩世不恭和悲观厌世的冰雪所覆盖，您就会衰老下去，即使您只有20岁。
而当您的天线巍然矗立着的时候，凭着高昂的乐观主义精神，您就有希望在80岁死去时仍然韶华不逝。