just in case if the muslim apologist tries to excuse the verse with saying that the word "heart" here is not referring to the organ itself, here's an argument that proves him wrong: there are hadiths that clearly say that the "qalb" is a "piece of flesh" (mudhgha).
http://sunnah.com/bukhari/2/45 http://sunnah.com/muslim/22/133Of course it can also mean psychological, but since it uses the word "piece of flesh", the meaning of a physical organ cannot be separated from the word qalb as it was understood by the prophet according to these hadiths. it would be ridiculous for a person to refer to mere psychological faculties excluding any reference to the physical organ as a "piece of flesh".
another point which comes to mind is that the verse says "Allah has not made for any man two hearts in
his body". The word "his body" here supports the position that the verse is talking about the heart in a corporeal sense. the intellect/emotion of a man is not confined in the body, but in his psyche. yet the quran here is talking about the heart which is in "the body". but then again I don't know how sound this argument is, since the Arabic word used is "jaufih". whether or not "jaufih" could refer to anything else other than the corporeal body, that I don't know.
I'm afraid you are wrong, it doesn't only mean the physical heart "piece of flesh".
Qalb (as well as Sadr and lub/albab) are frequently used in a metaphorical sense in the Qur'an. It is very often used as a metaphor for the mind and the seat of thinking, comprehension, feelings and emotions.
For example:
"The have hearts with which they do not understand" (7:179)
لهم قلوب لا يفقهون
But as Zaotar rightly says:Ironically that aya is even less correct when taken as a metaphor instead of literal biology. Having two biological hearts is rare. Having opposing feelings of love is a basic human condition.