I THINK,THEREFORE I AM

We have already seen that people disagree on many important issues,about the ethical rules of conduct,about the meaning of justice,and about whether God exists.It is no wonder that under these circumstances we ask the question “What can I know?” It is not surprising,either,that because of the uncertainties of our knowledge many people become “skeptics”.What is surprising is to discover how the word skeptic has changed over the course of time.Today we think of the skeptic as a person whose basic attitude is one of doubt.But the original Greek word,skeptical,from which skeptic is derived,meant something rather different,namely,“seekers” or “inquirers”.In the fourth century BC,a man by the name of Pyrrho（361-270 BC）founded a school of philosophy whose members were called Skeptics.Their original purpose was to achieve a way of thought that could lead to mental peace and calmness.One of their later writers,Sextus Empiricus（ca.200 AD）,pointed out that people were disturbed by the contradictions in things and plagued by doubt as to which alternatives they should believe.The Skeptics thought that if they could by investigation determine truth from falsehood they could attain tranquility of mind.They were struck,however,by the alternative conceptions of truth different philosophers proposed.They also noticed that people who searched for truth could be placed into three groups:（1）those who think they have discovered the truth（and those the Skeptics called dogmatists）;（2）those who confess they have not found it and also assert that it cannot be found（the Skeptics also considered this a dogmatic position）;and finally（3）those who continue to search for truth.Unlike the first two,said Sextus（in his Pyrrhonic Sketches）,“the Skeptics keep on searching… We end by ceasing to dogmatize.” The Skeptics had no doubt that they lived in a real world.They only wondered whether this world had been accurately described.While they continued to search for truth,they organized their daily life around four items,which Sextus calls（1）the guidance of nature,（2）the constraints of the feelings,（3）the tradition of laws and customs,and（4）instruction in the arts of work.Each one of these contributes,he says,to successful and peaceful living,and not one of them requires any dogmatic interpretation or evaluation,only acceptance.

Centuries later,Michel de Montaigne（1533-1592）adopted for his own the formula developed by Pyrrho and Sextus,saying（in his Essays）,“Pyrrho did not want to make himself into a stone;he wanted to make of himself a living man,discoursing and reasoning,enjoying all pleasures and natural commodities,using all of his bodily and spiritual parts regularly and properly.” Montaigne thought that a good place to begin the search for truth is one’s own personal experiences,because he believed that “every man carries within himself the whole condition of humanity.” Human experiences,he thought,could be described clearly and accurately and did not have to be obscured by technical language.“My page,” he writes,“makes love and knows what he is doing.But read to him Leo Hebraeus or Ficino where they speak of the actions and thoughts of love,and he can’t make head or tail of it.” However attractive Montaigne’s creative skepticism was,the urge to discover a solid basis for intellectual certainty persisted.In a fascinating manner,Rene Descartes（1596-1650）used the method of doubt to establish that solid base.There is,he said,a limit to what we can doubt;we cannot doubt our own existence.Whether my thinking is right or wrong,occurs while I am asleep or awake,it is nevertheless I who think.For this reason there can be no doubt that I exist;the fact is that “I think,therefore I am.” Throughout our discussion of various answers to the question “What can I know?” we will observe an intriguing alternation between the mood of skepticism and the desire for certainty.