英语原文
Possession for its own sake or in competition with the rest of the neighborhood would have been Thoreau's idea of the low levels. The active discipline of heightening one's perception of what is enduring in nature would have been his idea of the high. What he saved from the low was time and effort he could spend on the high. Thoreau certainly disapproved of starvation, but he would put into feeding himself only as much effort as would keep him functioning for more important efforts.

Effort is the gist of it. There is no happiness except as we take on life-engaging difficulties. Short of the impossible, as Yeats put it, the satisfaction we get from a lifetime depends on how high we choose our difficulties. Robert Frost was thinking in something like the same terms when he spoke of “The pleasure of taking pains”. The mortal flaw in the advertised version of happiness is in the fact that it purports to be effortless.

We demand difficulty even in our games. We demand it because without difficulty there can be no game. A game is a way of making something hard for the fun of it. The rules of the game are an arbitrary imposition of difficulty. When someone ruins the fun, he always does so by refusing to play by the rules. It is easier to win at chess if you are free, at your pleasure, to change the wholly arbitrary rules, but the fun is in winning within the rules. No difficulty, no fun.

参考译文
梭罗所理解的“低层次”，即为了拥有而去拥有，或与所有的邻居明争暗斗而致拥有。他心目中的“高层次”，则是这样一种积极的人生戒律，即要使自己对自然界永恒之物的感悟臻于完美。对于他从低层次上节省下来的时间和精力，他可将其致力于对高层次的追求。勿庸置疑，梭罗不赞成忍饥挨饿，但他在膳食方面所投入的精力仅果腹而已，只要可确保他能去从事更为重要的事务，他便别无所求。

殚精竭虑，全力以赴，便是其精髓所在。除非我们愿意直面那些需要我们全身心投入的艰难困苦，否则便不会有幸福可言。正如叶芝所言，除却某些不可能的情形，我们于人生中所获取的满足皆取决于我们在多高的境界中选择我们所愿意面对的艰难困苦。当罗伯特·弗罗斯特言及“以苦为乐”时，他内心所思，大体如此。商业广告中所宣扬的那种幸福观，其致命的缺陷就在于这样一个事实，即它宣称，一切幸福皆唾手可得，不费吹灰之力。

即便于游戏之中，我们也需要有艰难困苦。我们之所以需要它，因为设若没有困难，便断无游戏可言。游戏即是这样一种方式，为了享受其中的情趣而人为地使事情变得不那么轻而易举。游戏中的种种规则，便是将困难武断地强加于人。当有人将情趣摧毁殆尽时，他总是因为拒不按游戏规则行事而使然。这犹如下棋；如果你随心所欲、心血来潮地去更改那些全然武断的游戏规则，这样去赢棋当然会更加容易。但下棋的情趣则在于，应在规则的限定范围内赢取胜利。一言以蔽之，没有艰难，断无情趣。