Neurobiology is the study of the brain, psychology is a wider field that includes neurobiology as a part of it. Psychology deals with consciousness more broadly, and some have even argued that it is actually the study of the human spirit or the soul. Jamal al-Din Zarabozo did some great contrasting between psychology and Tazkiyyah al-Nafs/Tasawuff in his “Purification of the Soul” which is an interesting book that otherwise misses the entire point of Tasawuff.
There are different perspectives in the field of psychology broadly speaking: psychoanalysis (Freudian), cognitive/behavioral, and biological (neurological). Freudian psychology is based on the idiosyncratic and semi-psuedoscience, but nonetheless very interesting, ideas of Freud and subsequent people that followed in his school (Carl Jung). Cognitive psychology deals with the way people think and patterns of thought, behavioral is similar but focuses more on patterns of behavior and how they affect the mind/spirit. Biological deals with neurochemicals, the brain as an organ, and looks at things from a physical scientific perspective.
Most modern psychologist/psychiatrist have become highly biological, reducing the brain, cognition, and consciousness in general to the result of a kind of vapor wafting over an electric neurochemical soup over the brain. This also gets into the theory of consciousness, which is as much a philosophical question as it is a psychological one.
At the real heart of modern psychology is Continental philosophy and more specifically Hegelian epistemology. These kinds of natural sciences were more or less seen as one large field and not highly specialized until Hegel came around. When Hegel attempted to prove, through a sophisticated and brilliant model, that you can ground truth and reality in the physical world – there became no need to do epistemology or metaphysics in Western philosophy. Since we could ground truth in the material world, Western intellectuals believed, it was now time to based our understanding of lesser truths – such as pertaining to human nature and the human mind/spirit – on that understanding.
Capitalism, socialism, secularism, modern science, modern history, anthropology, and psychology all required this fundamental assumption that there is no noumenon (phenomenon being the physical world that we experience, noumenon referring to things outside of empircal deduction)
In Islamic history we had two major disciplines that discussed similar topics to modern psychology/psychiatry – Tasawuff and Hikmah. Tasawuff dealt with the study of human character and behavior through Akhlaq/Adab disciplines. The Sufis believed you could refine a person’s spirit/heart through refinement of their outer character. Additionally, they dealt with internal mental and spiritual issues through a very elaborate and sophisticated system of spiritual diseases and cures, along with a lot of discussion on the levels a person’s soul can go through in life and analysis as to what makes a heart pure or impure
This is distinct from Hikmah, although they are inter-related. Hikmah was a form of medical science which was informed by medical traditions that the Muslims encountered, then adapted and developed to suit the needs and beliefs of the Muslims. It also drew on pre-Islamic medical traditions. Ultimately, the most advance Hukama took their science from the Qur’an and Sunnah – famous individuals like ibn Sina and also ibn al-Qayyim.
According to the Hukama, the human being was composed of three components – Sama’, Ard, and Bayn. The Sama’, Heavenly, component was the Ruh (soul) which Allah puts in the body and also raises up at night. This is the vehicle for true knowledge. The Ard component is the flesh and body of the human, which comes from turab (dirt). The Bayn component was the Rizq of the person, which comes from water, food, and air – turns into blood – and ultimately becomes a personhood.
The hukama also developed systems for treating the physical and spiritual heart, alongside with treatment of the mind for people that suffered from junnun (insanity, mental illness). Junnun was thought to come from Jinn. Jinn according to the Hukama, discussed by al-Razi in Mafatih al-Ghayb, referred to a wide variety of unseen entities. The Hikmah conceptualization of Jinn includes the standard invisible entities similar to humans but made of smokeless fire, but also includes any invisible entities of that nature – conscious or not. Malicious unseen entities with inflammatory capabilities are called Shayatin, or Shaytan, and these are what affect the body, mind, and spirit.
Since Muslims did not take empiricism as their basis for their theory of the mind, diseases of the mind, or treatment of the mind; the Islamic dual approach of Tasawuff and Hikmah varies very drastically from modern psychology and psychiatry.
Psychology and psychiatry make the assumption that the only truths we can know about a human being are what are known by the senses. Therefore, human beings are an animal like any other animal, the product of random permutations in nature, fundamentally flawed and accidental. The way to improve upon the mind is to utilize our logic and science in order to change it so that it is more according to what is reasonably best.
Tasawuff and Hikmah assume that Allah created us in perfection – spiritually, mentally, emotionally, and physically. However, it is only our own deviation, or the deviation of others, that affects this Taharah Adamiyyah. In order to rectify a person, all people must constantly undergo a process of Tazkiyyah, in order to move them from deviation onto the Straight Path. The ideal man to the Sufi or the Hakim is one who is just as how Allah made him and intended him to be, without modifying or changing his nature.
Conclusion: modern psychology and Tasawuff/Hikmah deal with many of the same issues from different lenses. They are neither mutually exclusive nor totally compatible. Tasawuff and Hikmah are the result of the ijtihad of ancient ‘ulama based on their knowledge, however they are fundamentally based on Islam. Psychology/psychiatry are also the product of human research, but they are fundamentally based on kufr. Muslims should take the conclusions and methodologies of modern psychology/psychiatry and incorporate what is good according to the principles of Tasawuff/Hikmah.
و الله تعالى اعلى و اعلم