 In Liber de homine, Llull acknowledges that man must know what man is, and as he is able to know himself, he will be able to know other men and, naturally, God as well. However, the knowledge that man can reach is different from the rest of the beings. Animals, for example, can only know through senses and imagination, whereas angels can only intellectually know through themselves. As man is constituted by a soul and a body, he can know through the senses but is not limited by them. He is capable of going up the ladder and understanding other beings through the principles; additionally, he can also go down the ladder and understand the principles through beings.