In his autobiography, Darwin himself speaks of his intellectual powers with extraordinary modesty. He points out that he always experienced much difficulty in expressing himself clearly and concisely, but (46) he believes that this very difficulty may have had the compensating advantage of forcing him to think long and intently about every sentence, and thus enabling him to detect errors in reasoning and in his own observations. He disclaimed the possession of any great quickness of apprehension or wit, such as distinguished Huxley. (47) He asserted, also, that his power to follow a long and purely abstract train of thought was very limited, for which reason he felt certain that he never could have succeeded with mathematics. His memory, too, he described as extensive, but hazy. So poor in one sense was it that he never could remember for more than a few days a single date or a line of poetry. (48) On the other hand, he did not accept as well founded the charge made by some of his critics that, while he was a good observer, he had no power of reasoning. This, he thought, could not be true, because the “Origin of Species” is one long argument from the beginning to the end, and has convinced many able men. No one, he submits, could have written it without possessing some power of reasoning. He was willing to assert that “I have a fair share of invention, and of common sense or judgment, such as every fairly successful lawyer or doctor must have, but not, I believe, in any higher degree.” (49) He adds humbly that perhaps he was “superior to the common run of men in noticing things which easily escape attention, and in observing them carefully.”
Writing in the last year of his life, he expressed the opinion that in two or three respects his mind had changed during the preceding twenty or thirty years. Up to the age of thirty or beyond it poetry of many kinds gave him great pleasure. Formerly, too, pictures had given him considerable, and music very great, delight. In 1881, however, he said: “Now for many years I cannot endure to read a line of poetry. I have also almost lost my taste for pictures or music.” (50) Darwin was convinced that the loss of these tastes was not only a loss of happiness, but might possibly be injurious to the intellect, and more probably to the moral character.
46. He believes / that (this very )difficulty may have had the compensating advantage (of forcing him to think long and intently about every sentence, // and thus enabling him to detect errors in reasoning and in his own observations.)
( 1 )本句是一个主从复合句，含有一个 that 引导的宾语从句;其主干是 he believes that ( difficulty may have had the advantage ) .
( 2 )宾语从句“ that this very … his own observations ”含有 of 引导的两个后置定语“ of forcing him to … his own observations ”;由于是分词短语作定语，且太长，翻译时要找到与主句的逻辑关系，翻译成非定语成分。
( 1 ) very
adv. 表示“很，甚，及其，非常，完全”等。例如： The very idea of cheating people again is distasteful to him. (他一想到还要欺骗人就感到很不是滋味。)
( 2 ) compensate
vi.&vt. 表示“补偿，赔偿，酬报”等。如： to compensate sb. for (为……向某人赔偿)， Nothing can compensate the young mother for the loss of her favrourite daughter. (年轻的妈妈丧失了自己心爱的女儿是任何东西也弥补不了的。)本句是其现在分词作定语，译成“弥补的，补偿的”。
( 3 ) advantage
n. 表示“优势，有利条件，利益，便利”等等。如： Many women think this is an advantage for men. (许多妇女认为这是男人的优越之处。) This hall combines the advantages of the ball room and of a meeting place. (这个大厅既可作舞厅 , 又可作会场。)
常用短语： take advantage of (利用，欺骗)， at an advantage (有利地)， be of advantage to (对……有利)， gain an advantage over/of ( 胜过 , 优于 ) 。
( 4 ) enable 见 2009 年 49 题解释。
( 5 ) detect
vt. 表示“发现，察觉，注意到”。例： The dentist could detect no sign of decay in her teeth. (牙医在她的牙齿上找不到蛀蚀的迹象。)表示“侦察出，查明(常与 in 连用)”。例如： He was detected in the act of stealing. (他在偷窃时被当场发觉。)此处是“查明，发现”的意思。
( 6 ) reason
n. 表示“理由 , 原因 , 动机 , 理智 , 前提”等。如： There are reasons for this great interest in the ideas, feelings, and actions of youth. (对年轻人的思想、感情和行动发生这样巨大的兴趣 , 自有它的道理。)
vt. 表示“说服 , 推论 , 辩论”。如： reason with sb. for/against sth. ( 因赞成 / 反对……同某人讲道理 / 辩论 ) 。
vi. 表示“推论 , 劝说 , 思考”。如： to reason a person out of fear (劝人别害怕)。
常用短语： it stands to reason (合乎道理)， with reason (有理由，合乎情理)。例如： He thinks, with reason, that I don ’ t like him. (他有理由认为我不喜欢他。)
他 ( 达尔文 ) 认为，正是这种困难起了弥补作用，使他长时间专注地思考每个句子，从而能在推理和亲自观察中发现自己的错误。
47. He asserted, // also, that his power to follow a long and purely abstract train of thought was very limited, / for which reason he felt certain // that he never could have succeeded with mathematics.
( 1 )本句是一个复杂的主从复合句，包括两个 that 引导的宾语从句、一个 for 引导的原因状语从句，主句的主干是 he asserted that (his power was very limited).
( 2 )主句所含的宾语从句中，主干是 his power was very limited; to follow a long and purely abstract train of thought 是不定式作后置定语，由于太长，可以处理成非定语成分。
( 3 )原因状语从句中所含的宾语从句是 he never could have succeeded with mathematics ，由于太长，将其放在宾补 certain 之后。
( 1 ) assert
v. 表示“宣称 , 断言 , 声明;维护 , 坚持”等。如： assert one ’ s rights (维护自己的权利)， assert sth. to be true (断言某事是真实的)， assert national independence (维护民族独立)。 本句中可译为“认为，断言”。
( 2 ) train
n. 表示“列车 , 行列 , 后果 , 顺序”等。如： a train of events (一连串的事件)。
v. 表示“(常与 to 连用)培养，教导，训练”。如： Mr. Hart has trained his daughter for years. (哈特先生已训练自己女儿多年。)
( 3 ) limit
n. 表示“界限 , 限度 , 限制”。例如： There is a limit to the amount of money I can afford. (我能付得起的钱数是有限的。)
vt. 表示“减少，限制 , 限定(常与 to 搭配)”。例如： My mother limits the amount of food that I eat. (我母亲限制我的饭量。)
( 4 ) follow
v. 表示“跟随 , 追随 , 追求;理解; 遵循”等等。如： I didn ’ t follow his line of reasoning. (我不明白他的推理方法。) We shall follow closely the latest advance of the subject in the world. (我们将密切注意世界上这一课题的最新进展。)
常用短语： as follows ( 如下 ) 。
48. (On the other hand), he did not accept as well founded the charge (made by some of his critics)/ that , while he was a good observer,// he had no power of reasoning.
( 1 )本句是一个复杂的由 as well 连接的并列句，其中还含有一个带让步状语从句的同位语从句，主句的主干是 he did not accept as well founded the charge.
( 2 ) while he was a good observer, he had no power or reasoning 是一个让步状语从句，也是 the charge 的同位语，需要单独翻译，再重复同位语的先行词。
( 3 )根据汉语逻辑关系，先译同位语从句，再译主句，并对其他成分作出适当调整。
( 1 ) as well 表示“也，又，同样”，连接并列成分，此处连接 didn ’ t accept 和 founded 两个否定谓语。
( 2 ) found
v. 表示“建立，创立;(与 on, upon 连用)建立在……基础上;以……为根据”等等。例如： a story founded on fact (以事实为根据的故事)。在本句中的 founded 表示“以……为根据的，有根据的”，但因为由 as well 连接，都是 didn ’ t 的否定内容，所以要译为“没有根据的”，这是理解和翻译本句话的关键。
( 3 ) charge
n. 表示“电荷; 费用; 主管 , 掌管;充电 , 充气 , 装料”等等。如： The charge carries a possible sentence of three years. (这项控告可能要判三年徒刑。)
v. 表示“装满;控诉(与 with 搭配) , 责令 , 告诫 , 指示 , 加罪于; 冲锋; 收费”等等。如： He was charged with stealing a car. (他被指控偷了一辆汽车。)
常用短语： in charge of ( 负责 ) ， charge sb. with sth. ( 控告某人某事 ) 。
49.He adds humbly / that perhaps he was “superior to the common run of men in noticing things // which easily escape attention, // and in observing them carefully.”
( 1 )本句是一个复杂主从复合句，有主句和含有一个定语从句的宾语从句组成，主句的主干是 he adds that (he was superior to the common run).
( 2 ) he was superior to … carefully 是宾语从句，其主干是 he was superior to the common run.of … carefully 是介词短语作定语，其中含有一个定语从句和两个现在分词短语，翻译时需译成非定语成分。
( 3 ) which easily escape attention 是 things 的定语从句，比较短，可以直接译成定语。
( 1 ) humbly 是 humble 的 adv., 表示“谦虚地”意思。
adj. 表示“卑下的 , 微贱的 , 谦逊的 , 粗陋的”。如： The doctor was humble about his work, although he cured many people. (这位医生虽然治好了许多人的病，但他对他的工作仍很谦逊。)
vt. 表示“使……卑下 , 挫 , 贬抑”。例如： humble sb ’ s pride ( 压某人的气焰 , 使某人丢脸 ) 。
( 2 ) superior
n. 表示“长者 , 高手 , 上级”。
adj. 常与 to 搭配，表示“较高的 , 上级的 , 上好的 , 出众的 , 高傲的”。例如： This western restaurant is superior to the one we went to last week. (这家西餐馆比我们上星期去的那一家好。)尽管本词表示比较，但不与 than 连用，要与介词 to 搭配。本句中可译为“比……更……”。
( 3 ) escape
v. 表示“(常与 from 连用)逃走;(液体等)漏出;避免，疏忽”。例如： escape from prison (越狱)， Nothing escaped his attention. (什么也逃不过他的注意。)
n. 表示“逃 , 逃亡，逃跑; 溢出设备; 出口; [植]野生”。
50. Darwin was convinced / that the loss of these tastes was not only a loss of happiness,// but might possibly be injurious to the intellect,/// and more probably to the moral character.
( 1 )本句是一个含有复杂宾语从句的主从复合句，主句的主干是 Darwin was convinced that (the loss was not only a loss of happiness but might be injurious to … ).
( 2 )宾语从句是一个由 not only … but ( also )引导的并列句，且 but(also) 之后是由 and 连接的又一个并列句。
( 3 ) and 后省略了部分成分，补全应该是“ might more probably be injurious to the moral character ”。
( 1 ) convince
vt. 表示“使相信，信服，说服”。例如： He convinced me that I should study law. (他劝我应该学法律。) It took many hours to convince the court of his guilt. (花费了许多个小时法庭才相信他有罪。)本句可译为“认为，确信”。
( 2 ) injurious 是 injury 的形容词，表示“有害的，致伤的(常与 to 搭配)”。例如： Smoking is injurious to health, especially to the lungs. (抽烟对健康有害 , 尤其对肺有害。)
( 3 ) intellect
n. 表示“理解力， 思维能力， 理智 , 智力;明智者 , 有才智的人”。例如： the intellect(s) of the age (当代有才智的人士 , 当代的知识分子)。
( 4 ) character
n. 表示“性格;特征;字”等。例如： He has a strong but gentle character. (他有坚强但温柔的性格。)