I will think that the sky, the air, the earth, colours, shapes, sounds, and all external things are no different from the illusions of our dreams, and that they are traps he has laid for my credulity; I will consider myself as having no hands, no eyes, no ﬂesh, no blood, and no senses, but yet as falsely believing that I have all these; I will obstinately cling to these thoughts, and in this way, if indeed it is not in my power to discover any truth, yet certainly to the best of my ability and determination