"I think, therefore I am." Will anybody explain to me as clearly as possible what this statement actually mean?
Descartes set himself a project --to doubt all things that could possibly be doubted. Even after discarding all the evidence of his senses, he was left with the conviction that his own existence was an indisputable fact he could apprehend and verify directly.
In other words, even if he was deceived about all the details of his existence, he had to exist in order to even be deceived. Thus I think, therefore I am. In the Cartesian view, the self-recognition of the thinking mind is the foundation of all real knowledge.