Huwa allathee jaAAala lakumu allayla litaskunoo feehi wannahara mubsiran inna fee thalika (surah Yunus: 67)

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(10:67) It is Allah alone Who has made the night that you may rest in it, and has made the day light-giving. Surely in that there are signs for those who give heed (to the call of the Messenger). *65

Huwal lazee ja`ala lakumul laila litaskunoo feehi wannahaara mubsiraa; inna fee zaalika la Aayaatil liqawmai yasma`oon

*65). What is being said here in a summary fashion requires some elaboration. The statement refers to philosophical inquiry which aims atdiscovering the reality underlying the physical phenomena of the universe. All those who do not look up to revelation in order to know what such reality is, have to fall back, willy-nilly, on philosophical inquiry. Whether a person ends up with atheism, polytheism or monotheism, he perforce has recourse to philosophical inquiry of some sort in order to arrive at some conclusion about reality. Likewise, the worth of the religious doctrines propounded by the Prophets can also be determined by resort to philosophical reflection after which a person is likely to arrive at some conclusion as to whether the reality to which the physical phenomena allude makes any sense or not. The soundness of the conclusion at which a person arrives totally depends, however, on the soundness of the method of philosophical inquiry that is adopted. If the method is sound, so would the conclusion be; and vice versa.
Let us now examine the methods that were adopted by different groups in this pursuit. Of these, the method used by the polytheists is based on superstition. As for the gnostic and ascetic hermits, even though they flaunt meditation as their characteristic method and claim their ability to penetrate the reality that lies beyond the phenomenal veil, their quest is based merely on conjecture. Likewise, what they claim to have observed is actually a product of their fancy. Swayed by it, they mistake their fancies for the truth.
Now, philosophers are guided in their quest for reality by speculation which, it would seem, is nothing less than conjecture. But realizing that their conjecture has no respectable ground upon which to stand, philosophers provide the crutches of logical reasoning and phoney rationalism to support their quest, and give it the imposing title of philosophical inquiry.
Then we come across scientists. In their own field, they resort to scientific methods of inquiry, but as soon as they enter the realm of the metaphysical, they abandon this method and proceed with guesswork and conjecture. The outlook of all these groups is impaired, afflicted with bias and prejudice of one sort or another. This makes them impervious to everything which is alien to them with the net result that they cling adamantly to their cherished ways. The Qur'an brands this kind of intellectual quest as essentially fallacious. It tells such people that the real cause of their malady is guesswork and conjecture in their pursuit of reality, and that they do not heed the reasonable counsel of others because of their deep-seated prejudices. The result is not only are they incapable of independently grasping reality, but their prejudice renders them incapable of arriving at any sound judgement regarding it even when it is expounded by the Prophets.
In sharp contrast to these fallacious methods, the Qur'an lays down an altogether different method to guide men in their quest of reality. This requires, first of all, that one should heed with open ears and consider with open minds the statements of those who claim to be expounding their doctrine about reality not on the basis of speculation or conjecture, nor on the basis of meditation or intuitive conviction, but on the basis of 'knowledge'. They should then proceed to consider the phenomena which form a part of man's observation or experience of the universe (called ayat - signs - in the Qur'anic parlance); to systematize all that they come to know in this manner and to seriously reflect whether the phenomena seem to testify to the reality underlying the phenomena to which these people [i.e. the Prophets] have drawn their attention. If one finds sufficient grounds to affirm the truths propounded by the Prophets, why on earth should anyone contradict such truths? In our view, this very method is the basis of the philosophy of Islam and it is regrettable that even Muslim philosophers abandoned it and set out to follow in the footsteps of Plato and Aristotle.
Not only does the Qur'an urge people, over and over again, to follow this method, but by frequently drawing attention to the physical phenomena and then showing how right conclusions can be derived from them, it also seems to train them to follow this method. Were one to consider even the present verse by way of example one would encounter reference to a couple of physical phenomena - night and day. The alternation of day and night is the outcome of an absolutely precise and well-regulated movement of the earth around the sun. This is an incontrovertible sign of the existence of an all-encompassing controller, of an all-powerful Lord Whose dominion embraces the whole universe. This alternation of day and night is also indicative of the infinite wisdom and purposiveness of the Creator since a lot of creatures of the earth depend upon it. This alternation is also indicative of the Providence, Mercy and Lordship of the Creator since it is evident that He Who has created all beings on earth has also made arrangements to cater to all their requirements.
What this unmistakably proves is that the Creator is the One Who fully controls the entire universe and that far from being arbitrary and capricious. He is Wise. His actions also go to show that in view of His benevolence and providence He alone deserves to be served and worshipped. Also, this alternation of day and night clearly reveals that anything which is subject to the system of alternation of night and day is a servant and not the Lord. All this being the testimony of the natural phenomena, how can it ever be entertained that the religious doctrines developed by polytheists on the basis of their guesswork and conjecture have even a shred of legitimacy?