Among various sources of error mentioned by the Qur'an, one is that of taking conjecture and hypothesis for certainty and conviction. If a person were to adhere to the principle of putting conviction only in certainties and of not confusing between conjectures and certainties, he would not fall into error. The Qur'an lays great emphasis on this problem, and has clearly stated in one place that one of the biggest errors of the human mind is pursuit of conjectures and hypotheses. In another verse, which is addressed to the Prophet (S), the Qur'an says:
وَإِنْ تُطِعْ أَكْثَرَ مَنْ فِي الْأَرْضِ يُضِلُّوكَ عَنْ سَبِيلِ اللَّهِ ۚ إِنْ يَتَّبِعُونَ إِلَّا الظَّنَّ وَإِنْ هُمْ إِلَّا يَخْرُصُونَ
“If thou obeyest the most part of those on earth, they will lead thee astray from the path of God: they follow only surmise, merely conjecturing. “(6:116)
In another verse, the Qur'an says:
وَلَا تَقْفُ مَا لَيْسَ لَكَ بِهِ عِلْمٌ
“And pursue not that thou has no knowledge of ... “(17:36)
This is the word of caution to mankind extended by the Qur'an, for the first time in the history of human ideas, warning mankind against this kind of error.
The second source of error in the reasoning process, which is particularly relevant in social issues, is imitation. Most people are such that they accept whatever beliefs that are current in their society. They adopt certain beliefs merely for the reason that they were followed by their preceding generation. The Qur'an bids people to carefully scrutinize all ideas and judge them by the criteria of reason --neither to follow blindly the conventional beliefs and traditions of their ancestors, nor to reject them totally without any rational justification.
It reminds us that there are many false doctrines that were introduced in the past, but were accepted by the people, and there are also certain truths that were presented in the distant past, but people resisted them on account of their ignorance. In accepting any ideas or principles, men are advised to make use of their intellects and rational faculties, and not to indulge in blind imitation. Very often, the Qur'an puts imitation of ancestors in direct opposition to reason and intellect:
وَإِذَا قِيلَ لَهُمُ اتَّبِعُوا مَا أَنْزَلَ اللَّهُ قَالُوا بَلْ نَتَّبِعُ مَا أَلْفَيْنَا عَلَيْهِ آبَاءَنَا ۗ أَوَلَوْ كَانَ آبَاؤُهُمْ لَا يَعْقِلُونَ شَيْئًا وَلَا يَهْتَدُونَ
“And when it is said to them: 'Follow what God has sent down', they say, 'No; but we will follow such things as we found our fathers doing.' What? Even if their fathers had no understanding of anything, and if they were not guided ?” (2:170)
The Qur'an constantly reiterates the view that the idea of antiquity of an idea is neither the evidence of its falsity, nor is it a testimony of its truthfulness. Antiquity affects material objects; but the eternal truths of existence never become old and outmoded. Truths like:
إِنَّ اللَّهَ لَا يُغَيِّرُ مَا بِقَوْمٍ حَتَّىٰ يُغَيِّرُوا مَا بِأَنْفُسِهِمْ
“God changes not what is in a people, until they change what is in themselves ...” (13:11)
are true for ever and ever. The Qur'an asks us to face issues with the weapon of reason and intellect. One should neither forsake a belief for fear of becoming the target of others' ridicule and banter, nor should he accept a belief just because it is upheld by some important and well- known persons. We should ourselves study and investigate the roots of all matters and draw our own conclusions.
A Third effective source of error pointed out by the Qur'an is:
Selfish motives tarnish virtue and merit,
A cascade of curtains gallops from the heart towards vision.
Unless one maintains objectivity and neutrality in every matter, he is unlikely to think correctly. Reason can function properly only in an atmosphere that is free of selfish desires and motives. A well-known anecdote of al-Allamah al-Hilli, can illustrate this point.
A problem of fiqh was put before al-Allamah al-Hilli: If an animal falls inside a well, and the carcass cannot be removed; what should be done with the well? Incidentally, during the same days, an animal happened to fall into the well in his own house, and it became inevitable for him to deduce an injunction to solve his own problem, too.
There were two possible ways to solve the issue: Firstly, the well should be totally closed, not to be used again; secondly, a fixed quantity of water should be emptied from the well and the rest water of well would be clean and usable. The 'Allamah realized that he could not give a completely impartial verdict about the problem without interference from his own personal interest. Accordingly, he ordered his own well be closed. Then, with an easy mind, free of the pressure of selfish motives. he turned to deducing the details of verdict in the second case.
The Qur'an contains a large number of warnings regarding the evil of submission to personal desires. The following is just one instance of it:
إِنْ يَتَّبِعُونَ إِلَّا الظَّنَّ وَمَا تَهْوَى الْأَنْفُسُ
“They follow nothing except conjecture, and what the self desires ... “(53:23)