The being that exists is man. Man alone exists. Rocks are – but they do not exist. Trees are, but they do not exist. Horses are, but they do not exist. Angels are, but they do not exist. God is, but he does not exist.
The proposition “man alone exists” does not mean by any means that man alone is a real being while all other beings are unreal and mere appearances or human ideas.
The proposition “man exists” means: man is that being whose Being is distinguished by the open-standing standing-in in the unconcealedness of Being, from Being, in Being. (Martin Heidegger)