I know that I exist; the question is, What is this 'I' that 'I' know.
Conquer yourself rather than the world.
It is contrary to reasoning to say that there is a vacuum or space in which there is absolutely nothing.
I am indeed amazed when I consider how weak my mind is and how prone to error.
And I shall always hold myself more obliged to those by whose favour I enjoy uninterrupted leisure than to any who might offer me the most honourable positions in the world.
And as it is the most generous souls who have most gratitude, it is those who have most pride, and who are most base and infirm, who most allow themselves to be carried away by anger and hatred.