“Some care is needed in using Descartes' argument. "I think, therefore I am" says rather more than is strictly certain. It might seem as though we are quite sure of being the same person to-day as we were yesterday, and this is no doubt true in some sense. But the real Self is as hard to arrive at as the real table, and does not seem to have that absolute, convincing certainty that belongs to particular experiences.”

Welsh mathematician and philosopher

Bertrand Russell was a Welsh mathematician and philosopher, and a founder of analytic philosophy. He became one of the leading philosophers of the 20th century, known for work in logic, set theory, and the philosophy of language. He also helped bring philosophy to a wider public through his books and commentary. Outside academic philosophy, he was widely known for his outspoken atheism, pacifism, and opposition to nuclear weapons, and he often wrote on social and political questions.