Physiology has its own share in exploring knowledge...

Physiology has its own share in exploring knowledge; also psychology, with its various schools, including the schools of introspectionism (al-istibtaniyya),[^6] behaviorism, functionalism (al-wazifiyya),[^7] and so on. Every one of these schools studies a various aspect of knowledge. After all of this, the role of philosophical psychology emerges to treat knowledge from its own perspective.

It investigates whether knowledge in essence is a material state of the nervous system or a pure spiritual state. In what follows, we will clarify those various aspects to the extent needed to light up the path of our investigation, and to show our position regarding materialism and Marxism. Knowledge on the Level of Physics and Chemistry On their own level of research, physics and chemistry treat the physical and chemical events that often accompany the acts of cognition.

These events are exemplified in the reflection of light rays from visible things, the influence of those electromagnetic vibrations on a healthy eye, the chemical changes that occur (p. 375) because of this, the reflection of sound waves from audible objects, the chemical particles that issue from odoriferous and flavored things, as well as other similar physical stimuli and chemical changes. All such events fall in the domain of the scientific application of physics and chemistry.

Knowledge on the Level of Physiology In light of physiological experiments, a number of events and processes that occur in the sense organs and in the nervous system, including the brain; were discovered. Even though such events are of a physical and chemical nature, as are the above processes, nevertheless, they are distinguished from those processes in that they occur in a living body. Thus, they have a certain relation to the nature of living bodies.

By means of such discoveries, physiology was able to determine the vital functions of the nervous system and the role that its various parts play in the acts of cognition. Thus, according to physiology, the brains are divided into four lobes: the frontal lobe, the parietal lobe, the temporal lobe and the occipital lobe. Each of these lobes has its specific physiological functions. The motor centers, for example, are in the frontal lobe.

The sensory centers, which receive messages from the body, are in the parietal lobe. The same is true of the sense of touch and that of pressure.