What is supported by what we have mentioned is that natural things do not accept nourishment except from their problems, but as for what does not cause problems with them, they do not accept nourishment from them absolutely. An example of this is that the generators of minerals, plants, and animals are composed of the four natures, and the generators do not accept nourishment except from them, because they contain a share of them, even if they are harmful. No one of creation could provide nourishment for his body, which is composed of these natures, from something other than these natures, or what is composed of them. Just as it is not possible for any natural body to accept nourishment except from something that is of the natures of which it is derived. Likewise, it is not possible for anyone to know something that does not have something similar to it at all. Do you not see that the soul does not accept from the mind except what it shares in it and conforms to it? And what it do