In mental substance or spiritual matter all the impulses emanating from a being's spiritual structure become shapes and images that the being in question creates and experiences with spiritual senses. Here the being can experience and create independently of physical matter. As it, with the same senses, can of course also see the creations and experiences of fellow beings in this substance, it is thus established as fact that the living being has here a field of experience and creation in which it can experience and create independently of the physical world and the physical organism. With this sensory structure it cannot, of course, experience the details of the physical world that appear in wave spectrums or wavelength ranges that cannot be sensed directly with the spiritual senses. This is the reason why living beings must have a physical organism and the physical sensory structure placed within it, by virtue of which the physical world, with its details and things, can be experienced.