Emphasis of the Quran on Reason

From: http://www.quranicteachings.co.uk/

Allah created man superior to animals by giving him the distinguished ability to reason, looking forward that he would make use of this prized possession. How could it be possible that Allah Himself would give man a faculty and did not intend and appreciate its use? It does not make sense. He has elaborated in the Quran that,
هُوَ الَّذِي خَلَقَكُمْ مِنْ تُرَابٍ ثُمَّ مِنْ نُطْفَةٍ ثُمَّ مِنْ عَلَقَةٍ ثُمَّ يُخْرِجُكُمْ طِفْلا ثُمَّ لِتَبْلُغُوا أَشُدَّكُمْ ثُمَّ لِتَكُونُوا شُيُوخًا وَمِنْكُمْ مَنْ يُتَوَفَّى مِنْ قَبْلُ وَلِتَبْلُغُوا أَجَلا مُسَمًّى وَلَعَلَّكُمْ تَعْقِلُونَ
“It is He Who has created you from dust; then from a sperm-drop; then from a leech-like clot; then does he get you out as a child; then lets you (grow and) reach your age of full strength; then lets you become old,- though of you there are some who die before;- and lets you reach a Term appointed; in order that you may use your reason.” [40:67]

Allah has bestowed His Guidance upon humans not for that they do not use their reason or intellect but on the contrary He has expounded that the very purpose of His Guidance, the Quran, is that people should use their reason.
إِنَّا أَنْزَلْنَاهُ قُرْآنًا عَرَبِيًّا لَعَلَّكُمْ تَعْقِلُونَ
“Indeed, We have sent it down as an Arabic Quran, so that you might encompass it with your reason.” [12:2]
إِنَّا جَعَلْنَاهُ قُرْآنًا عَرَبِيًّا لَعَلَّكُمْ تَعْقِلُونَ
“Indeed, We have rendered it an Arabic Quran, so that you might encompass it with your reason.” [43:3]

The importance of using the faculty of reasoning is such that Allah has severely condemned those who do not make use of it. He says in the Quran,
إِنَّ شَرَّ الدَّوَابِّ عِنْدَ اللَّهِ الصُّمُّ الْبُكْمُ الَّذِينَ لا يَعْقِلُونَ
Verily, the vilest of all creatures in the sight of God are those deaf, those dumb ones who do not use their reason. [8:22]
وَلَقَدْ ذَرَأْنَا لِجَهَنَّمَ كَثِيرًا مِنَ الْجِنِّ وَالإنْسِ لَهُمْ قُلُوبٌ لا يَفْقَهُونَ بِهَا وَلَهُمْ أَعْيُنٌ لا يُبْصِرُونَ بِهَا وَلَهُمْ آذَانٌ لا يَسْمَعُونَ بِهَا أُولَئِكَ كَالأنْعَامِ بَلْ هُمْ أَضَلُّ أُولَئِكَ هُمُ الْغَافِلُونَ
And most certainly have We destined for hell many of the invisible beings and human being who have hearts with which they fail to grasp the truth, and eyes with which they fail to see, and ears with which they fail to hear. They are like cattle -nay, they are even less conscious of the right way it is they, they who are the [truly] heedless! [7:179]

Allah has urged humans in the Quran to ponder upon whatever there is in the universe and elucidated that in His creations, there are signs (towards the Truth) for those who use their reason.
إِنَّ فِي خَلْقِ السَّمَاوَاتِ وَالأرْضِ وَاخْتِلافِ اللَّيْلِ وَالنَّهَارِ وَالْفُلْكِ الَّتِي تَجْرِي فِي الْبَحْرِ بِمَا يَنْفَعُ النَّاسَ وَمَا أَنْزَلَ اللَّهُ مِنَ السَّمَاءِ مِنْ مَاءٍ فَأَحْيَا بِهِ الأرْضَ بَعْدَ مَوْتِهَا وَبَثَّ فِيهَا مِنْ كُلِّ دَابَّةٍ وَتَصْرِيفِ الرِّيَاحِ وَالسَّحَابِ الْمُسَخَّرِ بَيْنَ السَّمَاءِ وَالأرْضِ لآيَاتٍ لِقَوْمٍ يَعْقِلُونَ
Verily, in the creation of the heavens and of the earth, and the succession of night and day: and in the ships that speed through the sea with what is useful to man: and in the waters which God sends down from the sky, giving life thereby to the earth after it had been lifeless, and causing all manner of living creatures to multiply thereon: and in the change of the winds, and the clouds that run their appointed courses between sky and earth: [in all this] there are messages/signs indeed for people who use their reason. [2:164]
وَفِي الأرْضِ قِطَعٌ مُتَجَاوِرَاتٌ وَجَنَّاتٌ مِنْ أَعْنَابٍ وَزَرْعٌ وَنَخِيلٌ صِنْوَانٌ وَغَيْرُ صِنْوَانٍ يُسْقَى بِمَاءٍ وَاحِدٍ وَنُفَضِّلُ بَعْضَهَا عَلَى بَعْضٍ فِي الأكُلِ إِنَّ فِي ذَلِكَ لآيَاتٍ لِقَوْمٍ يَعْقِلُونَ
And there are on earth [many] tracts of land close by one another [and yet widely differing from one another]; and [there are on it] vinyards, and fields of grain, and date-palms growing in clusters from one root or standing alone, [all] watered with the same water: and yet, some of them have We favoured above others by way of the food [which they provide for man and beast]. Verily, in all this there are messages/signs indeed for people who use their reason! [13:4]
وَسَخَّرَ لَكُمُ اللَّيْلَ وَالنَّهَارَ وَالشَّمْسَ وَالْقَمَرَ وَالنُّجُومُ مُسَخَّرَاتٌ بِأَمْرِهِ إِنَّ فِي ذَلِكَ لآيَاتٍ لِقَوْمٍ يَعْقِلُونَ
And He has marshalled to your service the night and the day, the sun and the moon, and the stars have also been made subservient by His command. They all function according to His laws. In these also there are signs for those who use their reason. [16:12]
وَمِنْ ثَمَرَاتِ النَّخِيلِ وَالأعْنَابِ تَتَّخِذُونَ مِنْهُ سَكَرًا وَرِزْقًا حَسَنًا إِنَّ فِي ذَلِكَ لآيَةً لِقَوْمٍ يَعْقِلُونَ
And [We grant you nourishment] from the fruit of date-palms and vines: from it you derive intoxicants as well as wholesome sustenance -in this, behold, there is a message/sign indeed for people who use their reason. [16:67]
وَمِنْ آيَاتِهِ يُرِيكُمُ الْبَرْقَ خَوْفًا وَطَمَعًا وَيُنَزِّلُ مِنَ السَّمَاءِ مَاءً فَيُحْيِي بِهِ الأرْضَ بَعْدَ مَوْتِهَا إِنَّ فِي ذَلِكَ لآيَاتٍ لِقَوْمٍ يَعْقِلُونَ
And among His Signs, He shows you the lightning, by way both of fear and of hope, and He sends down rain from the sky and with it gives life to the earth after it is dead: verily in that are Signs for those who use their reason. [30:24]
وَاخْتِلافِ اللَّيْلِ وَالنَّهَارِ وَمَا أَنْزَلَ اللَّهُ مِنَ السَّمَاءِ مِنْ رِزْقٍ فَأَحْيَا بِهِ الأرْضَ بَعْدَ مَوْتِهَا وَتَصْرِيفِ الرِّيَاحِ آيَاتٌ لِقَوْمٍ يَعْقِلُونَ
And in the alternation of the night and the day, and in the means of sustenance which Allah sends down from the Height, reviving the earth which had been lifeless, and in the change of winds and seasons - in all this are Signs for people who use their reason. [45:5]
أَفَلَمْ يَسِيرُوا فِي الأرْضِ فَتَكُونَ لَهُمْ قُلُوبٌ يَعْقِلُونَ بِهَا أَوْ آذَانٌ يَسْمَعُونَ بِهَا فَإِنَّهَا لا تَعْمَى الأبْصَارُ وَلَكِنْ تَعْمَى الْقُلُوبُ الَّتِي فِي الصُّدُورِ
Do they not travel through the land, so that their hearts (and minds) may thus use reason 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. [22:46]

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