雙語暢銷書《艾倫圖靈傳》第3章:思考什麼是思考(87)
An 'infinity of symbols', he wished to argue, did not correspond to anything in reality.
It might be argued that there was an infinity of symbols, in that an Arabic numeral such as 17 or 999999999999999 is normally treated as a single symbol.
假設有無限個符號，就像：一個阿拉伯數，比如17或者999999999999999，通常被看成一個單獨的符號。Similarly in any European language words are treated as single symbols (Chinese, however, attempts to have an enumerable infinity of symbols).
同樣，在各種歐洲語言中，一個單詞被看成一個單獨的符號（中文似乎擁有無限可列個符號）。
But he disposed of this objection with the observation that the differences from our point of view between the single and compound symbols is that the compound symbols, if they are too lengthy, cannot be observed at one glance.
接着，他否定了這樣的假設：對我們來說，一個符號和一組符號的區別是，組合符號如果太長，就不能一下子識別。This is in accordance with experience. We cannot tell at a glance whether 9999999999999999 and 999999999999999 are the same.
這是符合日常經驗的，我們不能只看一眼，就說出9999999999999999和999999999999999是否一樣。Accordingly, he felt justified in restricting a machine to a finite repertoire of symbols. Next came a most important idea:
因此，他認爲應該限定機器只使用有限的符號。接下來，最重要的想法出場了：The behaviour of the computer at any moment is determined by the symbols which he is observing, and his 'state of mind' at that moment.
計算者（computer）在任意時刻的行爲，都取決於他正在看着的方格，和他此時的思維狀態。We may suppose that there is a bound B to the number of symbols or squares which the computer can observe at one moment.
假設有一個界限B，來限定計算者可以同時有多少條視線，也就是他同時可以看到多少個方格。If he wishes to observe more, he must use successive observations.
如果他想看到更多，那他必須分成多次來看。We will also suppose that the number of states of mind which need to be taken into account is finite.
我們假設思維狀態的數量也是有限的。The reasons for this are the same character as those which restrict the number of symbols.
這樣做的原因，與限制符號的數量一樣。If we admitted an infinity of states of mind, some of them will be 'arbitrarily close' and will be confused.
如果我們認爲思維狀態有無限多個，那麼其中一些就會無限地相近，並混淆起來。Again, the restriction is not one which seriously affects computation, since the use of more complicated states of mind can be avoided by writing more symbols on the tape.
而且，這樣的限制對計算並不會造成嚴重的影響，因爲可以通過在紙帶上記錄更多的符號，來避免出現更復雜的思維狀態。
