Whether one speaks of numbers, the Platonic Forms, or anything similar, these abstractions—stripped of every positive and negative qualification—have no existence save as notions the mind itself fabricates.

If someone protests, “I can posit ‘man’ while divesting him of both external and mental existence,” the answer is: that very positing occurs only in the mind, exactly as the mind can posit other impossibilities—for example, an existent that is neither necessary nor contingent, neither self-subsistent nor dependent on something else, neither separate from other things nor conjoined with them. All of this exists solely as a mental fiction. Not everything the mind can posit is capable of existing outside the mind; nor is every judgment a person passes on what he imagines and posits necessarily a sound judgment about what actually exists; nor does every concept the intellect can entertain thereby acquire real existence.

In fact, the intellect envisions and hypothesizes things while sometimes knowing they are impossible, sometimes knowing they are possible, and sometimes remaining ignorant of whether they are possible or impossible in the real world. This last state is what is called “mental possibility.” The term “possibility” is thus used in two senses: mental possibility and external possibility. Mental possibility arises when an idea is presented to the mind and the mind does not perceive any contradiction in it; it therefore says, “This might be,” not because it knows the thing to be possible, but simply because it does not know it to be impossible—even though, in reality, the thing may in fact be impossible.

External possibility, by contrast, is to know that something can exist in the real world. One learns this by ascertaining that it actually exists, or that something comparable exists, or that something even less likely to exist nevertheless does exist. If that which is furthest removed from existence is found to be real and possible, then something closer to existence is, a fortiori, more deserving of being deemed possible.

The Qur’an’s Method for Demonstrating the Possibility of Resurrection

This, precisely, is the method the Qur’an employs to establish the possibility of the Resurrection.

At times it recounts cases of people whom Allah caused to die and then revived, as in His words about the people of Moses:

“And [recall] when you said, ‘O Moses, we will never believe you until we see Allah openly.’ So the thunderbolt seized you while you were looking on. Then We revived you after your death so that you might be grateful.” (Q 2:55–56)