There are certain ignorant philosophers in this day and age, who attribute all positive advancement to the brain. However, such people do not realise that the brain only possesses the ability to weigh arguments and evidence. Although it is the brain that possesses the faculty of reflection and retention, the heart possesses a quality which moves it to the position of a chief. The mind follows a forced, mechanical process, while the heart is free of this and functions in an unforced, natural way. It is for this reason that the heart holds an affinity with the Lord of the Throne, and is able to determine the truth merely through its faculty of sense, without any evidence or proof. This is why it is narrated in a hadith:
Meaning, seek a verdict from your heart. One has not been instructed to seek a verdict from one’s brain. It is the heart with which the line of divinity is linked. No one ought to view this as improbable. This concept is deep and difficult indeed, but those who are experienced in purifying the soul know that all good values inherently exist within the heart. If the heart had not possessed these powers, the very being of man itself would be without purpose. Sufis who remain engaged in mystic practices and those who undertake spiritual exercises know well that the heart can be seen to visibly emit columns of light, which flow towards the sky in the form of a straight line. This is a clearly visible and categorically established phenomenon. I cannot explain this with any specific examples, but indeed, those who have had to engage in exercises in spirituality, or who have sought to traverse the stages of the spiritual quest, have found this spectacle and experience to be true.
Hazrat Mirza Ghulam Ahmad (as), Malfuzat – Volume II (Tilford, Surrey: Islam International Publications Ltd., 2019), 119-120.