The next argument I would like to present in favour of God, albeit logical and relating to the ‘ought-to-be’ stage of certainty concerning God, provides a sure and definite sign to God for the discerning. One must not assume that logical arguments are just hypothetical and cannot lead to any degree of certainty concerning God. Anyone who has this idea has completely misunderstood. The ‘ought-to-be’ stage concerning God is a stage of certainty, just as the ‘is’ stage is a stage of certainty. The difference is that the ‘ought-to-be’ stage does not provide the utmost certainty provided by the ‘is’ stage, and it is not as assuring and as comforting; nevertheless, no wise person should doubt that it is a stage of certainty.
There are various stages of certainty. One stage of certainty is that which is achieved by reasoning, when we infer the existence of something by observing some of its effects. For instance, when we observe smoke far off in a forest, we infer that there is a fire giving off smoke, as there cannot be smoke without fire, and that gives us the certainty of reason. In Quranic terminology this is called ‘ilmul-yaqin; i.e. the certainty through inference in the absence of any direct observation. Clearly, the ‘ought to be’ stage belongs to this category, as we infer the existence of God from signs, not from direct observation. When we see fire with our eyes, or experience its heat, the ‘ought to be’ stage of certainty changes to ‘is’ stage of definitive certainty. In other words, in the ‘ought to be’ stage we believe in God on the basis of reasoning and in the ‘is’ stage we no longer depend on reasoning; rather, we graduate to a kind of physical observation.
It would not be out of place to mention the other two stages of certainty described by the Holy Quran. The first, as mentioned above, is that of ‘ilmul-yaqin, in which certainty about something is acquired by logical inference from its signs. The second stage is that of ‘aynul-yaqin [the certainty of sight], which marks the beginning of observation and no longer requires reasoning. For instance, when we walk in the direction of the smoke and begin to see the fire with our eyes, then we do not have ‘ilmul-yaqin only, but acquire ‘aynul-yaqin; i.e. we believe on the authority of direct observation and inference plays no part in it.
There is another stage above this, called haqqul-yaqin [the certainty of experience] in Quranic terminology. This stage is reached when man gets so close to the fire that he experiences its heat and not only sees the fire but also benefits from its heat and can distinguish the right path from the wrong one in its light. This is the ultimate stage of certainty beyond which there is no other stage. Although there are several sub-stages within this ultimate stage and everyone attains their place according to their capacity and effort. We need not go into the details here. In short, there are several stages of certainty, and the stage of ‘ought to be’, called ‘ilmul-yaqin, the one we are discussing here, is an elementary stage.