Infused into man's bodily composition...
Infused into man's bodily composition, this spirit which God relates to Himself and is thus the closest of all things to Him is independent of the body and separate from it, beyond the reach of matter and all its attributes and properties. Even the materialists despite all the differences of opinion and ideology that separate them from the followers of religion do not go so far as to deny the existence of something called the spirit.
They regard sciences such as psychology and psychiatry as valid, but part company with the theologians and metaphysicians on the existence of a second reality in man that subsists apart from the material body and independently of it; this reality has a nature peculiar to itself and is the source of thought and reflection in man. This does not mean that body and spirit are two realities that are separate from each other, in the sense of each expressing itself completely independently of the other.
They are two realities that are connected to each other while being utterly different in their essences. Beliefs of the Materialists The thoughts of the materialists on this topic are based on the assumption that a substance called the spirit does not exist independently of matter. They insist that all the activities of the brain are controlled by the laws of matter and result from physical causes and chemical reactions of the brain cells and nerves.
Our nervous system at all times links our perceptions to a central organ, the brain, and these perceptions in turn give rise to a single and indivisible whole. The phenomena that we associate with the spirit are nothing other than physico-chemical reactions. When the brain cells are exhausted and the reciprocal influence of the bodily organs comes to an end, so that the cells cease motion and reproduction, nothing is left of the essence of man save a material form.
It is therefore impossible to accept any kind of spiritual immortality or the existence of an autonomous, independent, supranatural entity in man, for both the first appearance and the subsistence of the “spirit” were caused by a spatially and temporally determined connection. Here the materialist and religious schools of thought part company decisively.
* * * * * If we accept the claims of the materialists, man will be like a machine, put together from different components and parts, and all traces of life and thought in him terminate utterly once the reciprocal influence of his material components comes to an end.