I am confused regarding the heart. I am giving a detailed account of my reservations. Please cearify my questions to me.
Verse 10 of Surah al-Baqarah reads: "In their hearts is a disease; and Allah has increased their disease." (Q 2:10)
By the word 'qulb' we mean heart. This word have been used in the Quran several times. You know that the ancient philosophers and the books considered it a centre of senses. But this is not correct according to the present psychological studies.
"The ancient philosophy and general understanding consider the heart a centre of senses and feelings. On the contrary, scientific researches indicate that the brain is the centre of motivation, incitation and the sensations." (Psychology for VCE, Valerie Clarke & Susan Gillet, 3/48)
Even love is considered to be a function of flow of blood from a part of a brain.
Now please tell how can we difine the word 'qalb' appearing in the Holy Quran. If we believe in the stance of Sufis that human heart is part of man's soul that performs many functions than it is again rejected by the modern psychologists.
"During the seventeenth century a French Philosopher Decartes presented the theory of two dimensions claiming that soul and body of two different things. The idea of independant existence of body and soul strikes to only the philosophers who cannnot understand the complications of human body. We gained some aquaintance with the functions of brain in the ninteenth century. Broca discovered the part of brain handling the speech communication functions in 1860. The scientific discoveries of 19th and the 20th century deny the theory of two dimensions and promote unity. They hold that no soul can exist without its body." (Psychology fro VCE, Valerie Clarke & Susan Gillet, 3/48)
The answer to your query is that the Holy Quran uses the word 'qulb' as a common expression. The Arabs ascribed some functions to heart 'qulb'. The Holy Quran saw no reason to deny this notion and used the same words and expressions for human characteristics as conventional among the Arabs. In tis sense, the Holy Quran does not promote the idea of an independant existence of both heart and the brain. The Holy Quran has been revealed for guidence. It finds no interest in reformation of psychology, astrology, biology and zoology or any other fields of science. Contrarily it has used the very common word to clearly express its message to the adressee.
The second anwer to your question is that the main defect of science and psychology is that they can observe the only things that exist phisically. The personality of man is a different thing that does not physically exist in the strict sense of the word and so we cannot pass any comments on it with the help of science. Human brain is a corporeal element. This led the scientists to discover many things about human brain. You are right in your thinking that they prefer the idea of unity rather than duality of body and soul. Consequently they consider brain a centre of all intellectual and psychological actions. Let us believe that scientists are right in thier observations; the question is does the Holy Quran favor their stance? The answer is not in the affirmative. The Holy Quran recounts the procdure of death in the following words:
"If you could but see how the wicked (do fare) in the flood of confusion at death! - The angels stretch forth their hands, (saying),"Yield up your souls: this day shall you receive your reward,- a penalty of shame, for that you used to tell lies against Allah" (Q 6:93)
وَلَوْ تَرَى إِذِ الظَّالِمُونَ فِي غَمَرَاتِ الْمَوْتِ وَالْمَلآئِكَةُ بَاسِطُوْا أَيْدِيهِمْ أَخْرِجُوْا أَنفُسَكُمُ الْيَوْمَ تُجْزَوْنَ عَذَابَ الْهُونِ بِمَا كُنتُمْ تَقُولُونَ عَلَى اللّهِ غَيْرَ الْحَقِّ (الأنعام-93)
This verse alludes to the fact that death is the separation of soul from the body. According to the scientists death occurs when the machinery of the body stops working. However, the word rūḥ according to the Holy Qur'an is different from the body. Obviously it has some functions. It seems that it uses the body to perform its various functions. That is why a body stops working when soul departs from it.
The observation of the modern experts and scientists is limited to the body and they consider it the main system. We could believe in science but we are forced to deny it in the light of divine guidance.
Now the question arises that what is the significance of similarity between body and soul. Does the soul present in each part of the body or does it control the whole body from a specific place. The Holy Qur'an has said nothing related to this issue. However, it points out the place of 'qulb' in a body. Surah al-Ahzāb (33) reads:
جَعَلَ اللَّهُ لِرَجُلٍ مِّن قَلْبَيْنِ فِي جَوْفِهِ (سورة الأحزاب/4)
"Allah has not made for any man two hearts in his (one) body." (Q 33:4)
Similarly a verse from Surah al-Hajj reads:
"Do they not travel through the land, so that their hearts (and minds) may thus learn wisdom and their ears may thus learn to hear? Truly it is not their eyes that are blind, but their hearts which are in their breasts." (Q 22:46)
أَفَلَمْ يَسِيرُوا فِي الْأَرْضِ فَتَكُونَ لَهُمْ قُلُوبٌ يَعْقِلُونَ بِهَا أَوْ آذَانٌ يَسْمَعُونَ بِهَا فَإِنَّهَا لَا تَعْمَى الْأَبْصَارُ وَلَكِن تَعْمَى الْقُلُوبُ الَّتِي فِي الصُّدُورِ(سورة الحج/46)
I believe that usage of the qalb in both the above verses does not allow taking it as a general term. Rather it seems that the heart in the chest performs some important functions. Had the brain the centre of all the functions heart would have been mentioned rather ambiguously without clarifying its station etc.
We see that during revelation of the Holy Qur'an, it was a general understanding of the Arabs that the earth is still and the sun revolves around it. The Holy Qur'an did not deny this conception but clarified the fact that all the celestial bodies are circulating in their orbits. The same method would have been adopted regarding heart. It would have been clarified that brain performs such functions instead of heart.
The verses also explicate that where the centre of man's powers is located. When the Holy Qur'an articulates that "the hearts in the chest are blind", it actually clarifies that whatever decision man makes depends on correct function of his heart to accept the truth. The difference in action of brain and the action of heart is similar to that of a function of a machine and commands of its operator. The scientists are right to hold that production unit is the brain but the main cause of bringing it into existence is totally a different thing.
(Translated into English by Abid Mahmood)