This famous saying of Descartes can be said to be "known all over the world", but few people really understand the meaning of this sentence, and many people understand it wrongly. So, what exactly does the phrase “I think, therefore I am” mean?

This requires the help of the "general skepticism" methodology mentioned above to understand. Certainties that are generally considered undoubtable are doubtful in Descartes' view. The objects of his doubts include not only the theories of previous generations, but also our senses. He does not trust them.

For example, can I now suspect that I am wearing a thick down jacket and sitting in front of the computer typing? You can doubt this, because the actual situation may be that I am sleeping in my pajamas on the bed now, and the scene in front of me is just a dream. Anyone who has watched the movie "Inception" knows that sometimes reality and dreams are indistinguishable. Without that little spinning top, how can you be sure that your current life is not a dream?

Speaking of this, many people will think of the allusion "Zhuangzi dreamed of butterflies". Did Zhuangzi dream that he turned into a butterfly? Or is the butterfly dreaming that he has become Zhuangzi? What is your basis for distinguishing the two?

Thoughts can doubt the object of thought, but they cannot doubt themselves. We can doubt everything that exists, but there is one thing that cannot be doubted, and that is the fact that "I am doubting" itself.

It must be noted that the "I" Descartes refers to here is not a physical body, but a subject of thought. "Strictly speaking, I am just a thinking thing, that is to say, I am just a mind, an intellect or a reason."

Another point that needs to be emphasized is that Descartes' "I think" The philosophical point of view "therefore I am" is not a logical inference, but is based on some kind of intellectual intuition. In other words, there is no causal relationship between "I think" and "I am".