260. The natural mind, being the integument and containing vessel of the higher degrees of the human mind, is reactive, and if the higher degrees are not opened, it acts in opposition to them, whereas if they are opened, it acts in harmony with them. We showed under the previous heading that the natural mind, being in the lowest degree, envelops and encloses the spiritual mind and celestial mind, which are higher in degree. We come now to the point to be demonstrated here, that the natural mind reacts in opposition to the higher or interior minds. The reason it reacts is that it envelops, encloses and contains them, and this cannot be the case without its reacting to them. For if it did not react, the interior or enclosed elements would break loose and thrust their way out and so drift away. It would be as if the integuments enveloping the human body were not to react to it. The organs which form the interior elements of the body would burst out and so fall apart. Or it would be as if the membrane enveloping the motor fibers of a muscle were not to react against the forces of those fibers in their actions. Not only would the action cease, but all the interior tissues would come undone. [2] The same is the case with every lowest degree in degrees of height. Consequently it is the same with the natural mind in relation to its higher degrees. For, as we said, the human mind consists of three degrees-natural, spiritual and celestial-and the natural mind is in the lowest degree. Another reason the natural mind reacts in opposition to the spiritual mind is that the natural mind consists not only of substances belonging to the spiritual world, but also of substances belonging to the natural world, as we said above in no. 257; and substances of the natural world by their very nature react against substances of the spiritual world. For substances of the natural world are in themselves lifeless, and are acted upon from without by substances of the spiritual world; and things which are lifeless, and are acted upon from without, by their very nature resist and so by their very nature react. It can be seen from this that the natural self reacts in opposition to the spiritual self, and that the result is combat. (The meaning is the same whether we call them the natural and spiritual self or the natural and spiritual mind.)