One famous example can be found in the “Chinese Room Argument” (Searle 1980) in which the philosopher John Searle argued that even if one were to build a machine that could take stories written in Chinese as input and then output coherent answers to questions about those stories, it would not prove that the machine itself actually understood what it was doing.  The argument rests on the claim that if you replaced the workings of the machine with a person who was not a native Chinese speaker who would then painstakingly follow a set of rules to transform the set of Chinese logograms input into other output symbols.  The claim is that that person would not understand the input and also would not know what the system is saying as its output, it is all meaningless symbol manipulation to them.  The conclusion is that this admittedly strange system could skillfully use the syntax of the language and story while the person inside would have no ability to understand the semantics, or meaning, of the stories (Searle 1980).  Replace the person with electronics and it follows that the electronics also have no understanding of the symbols they are processing. This argument, while provocative is not universally accepted and has lead to decades worth of argument and rebuttal (see the entry on  the Chinese room argument).  