Why is there something rather than nothing?

It’s a question that we all ask many times in our lives. It’s often said that philosophy begins in wonder, and the child is the greatest philosopher because the child isn’t too afraid to ask, “why?” The ultimate question is “why anything?”

It’s generally assumed that this question has no answer. Most philosophers have skated around the question — there is much written about the nature of the universe and our place in it, but little outside religious texts that elaborate on why it exists in the first place.

There are creation legends from the innumerable faiths, but only some examine divine reason itself. It is in the medieval period, as the empires of Islam and Christianity came into contact, that philosophy and theology were melded to probe at the heart of existence like never before.

Drawing from the philosophies of the ancient world, scholars developed rational theories for the existence of God and the purpose of the universe. These were aligned to the scriptures of religion, or at least did not contradict them. From there came investigations into the breadth and complexity of the material universe.

The unique and all-powerful God of Ibrahim is at the heart of these systems, while what was preserved of Aristotelianism and Platonism loom in the intellectual frameworks, despite their pagan origins.

The Persian philosopher Ibn Sina was the among the first to attempt to comprehensively answer the ultimate question. The philosopher started with a first principle, something we all intuitively know — everything around us is caused.

The seat you are likely sat in was made by people from raw materials. Those people were conceived in the wombs of their mothers, the raw materials of the chair — be they wood, plastic, or metal — were created by natural processes over many years.

If we keep going back in the chain of causes, we’ll see that the atoms of your chair were forged in the vast furnace of the universe, as were the atoms of the designers and makers of the chair.

We understand how things are caused. But what caused everything taken as a whole? If we know the answer to that question, we’ll come closer to know why there is something and not nothing.

The chair exists, but it isn’t the case that it must exist. We may or may not exist, in fact — it doesn’t take a huge leap of the imagination to contemplate even your own inexistence. Our essence — what makes us what we are — is separate from our existence. So how is there existence?

By demonstrating that one thing must exist, Ibn Sina shows how all things and anything can exist. In this scheme there is a “necessary existent” from which all other “existents” emanate.

By a master-stroke of reason, the philosopher goes on to make the case that the necessary existent must be God. In effect, Ibn Sina works backwards through causation to assert the existence of the very origin of being — God — before proceeding to confirm the attributes of God, and to describe how God is responsible for the universe and the diverse reality that we inhabit. He called this argument “The Proof of the Truthful.”

It’s an ambitious and even audacious exercise of intelligence fitting for Ibn Sina, a prolific polymath and one of the world’s most influential thinkers.

In the Western world, where he is principally known by his Latinized name “Avicenna”, the philosopher was profoundly influential on the development of Medieval Christian philosophy, probably via translations of his work made in the Caliphate of Córdoba (modern Spain and Portugal).

Europe was reintroduced to Aristotle through exposure to Islamic thought, which included “Latin Avicennism” as a dominant strand in the twelfth century. Thomas Aquinas synthesized Aristotelianism and Christian theology thanks to the philosophical innovations of Ibn Sina.

Ibn Sina was born in the village of Afshana, near Bukhara, the wealthy and culturally rich capital city of the Samanid dynasty situated on the Silk Road. He spent his formative years in the city, starting his career as a lawyer and doctor in circles close to the ruling dynasty.

Practising medicine for the city’s rulers allowed him access to the literature of the palace library, which included translations of surviving ancient Greek philosophical and scientific texts.

These texts were saved from oblivion and amassed in libraries across the Islamic world at the instigation of the Abbāsid caliphate. The intellectual enterprise that had radiated out of Baghdad  for two centuries previously had fostered a culture replete with philosophical and scientific innovations centuries before the European Renaissance.

From his learning Ibn Sina produced a vast body of writings, most notably on medicine and philosophy, but also on the natural sciences, psychology, theology, and mathematics. He was also a prolific poet, composing in both Arabic and Persian.

His most notable works to modern readers are The Canon of Medicine, a medical encyclopedia which provided the foundation of early modern medicine, and The Healing, a vast, multi-volume philosophical and scientific encyclopedia that sought to provide a coherent and integrated explanation for everything.

It is through the example of The Healing — titled as such because it is intended to “heal” ignorance of the soul — that we can appreciate just how much a single human being can achieve. It is a magisterial and intricate work in four parts — logic, science, mathematics, and metaphysics — comprehensively fusing science and philosophy.

As a philosopher, Ibn Sina was principally exposed to the works of Aristotle, and commentary on Aristotle’s work by followers (known as “Peripatetics”) as well as Neoplatonists like Plotinus, Porphyry, and Proclus. It’s worth noting that the Six Enneads of Plotinus, the most significant of the Neoplatonic works available, was a paraphrase misattributed to Aristotle and known in that time as The Theology of Aristotle.

It is Aristotelian ideas that form the basis of Ibn Sina’s understanding of the universe, but Neoplatonism that informs his theory of our place in the universe and our relation to God.

The fundamental distinction of Ibn Sina’s philosophical legacy lies in the distinction between essence — what things are, and existence — how things are. This leads him beyond Aristotle in his theory of everything and God.

The concept of essence derives from Aristotle, who used phrases like “the what it is” and “the what it is to be”. Essence is that which cannot be taken away from something without it ceasing to be what it is. Essence allows the distinction between things that exist. A horse has an essence distinct from a human being, for example.

But, at the same time, essence does not guarantee the existence of something. From merely knowing what a thing is, you cannot infer that it exists. There are an infinite number of things that can exist in our minds, but not in reality.

The philosopher gives the example of horses. You have a particular horse, and universal “horseness” that makes the horse a horse and not anything else. But universality is not included in the definition of horseness itself, universality is attached to horseness.

He wrote, “Oneness is an attribute that conjoins with ‘horseness’, whereby ‘horseness’ with this attribute becomes one.” (Book of Healing, Metaphysics, 5.1)

The horse is not a horse without the “oneness” of horseness, but neither is universal horseness nor the particular horse existing without the “attributes” of universality or particularity. While this seems academic, it does underlie Ibn Sina’s grand scheme of existence.

The particular horse, and its universal “horseness” must depend upon something else for existence — there’s nothing in the essence of a horse that says it must exist.

The philosopher defines three modes of how the essence relates to its existence — things are impossible, contingent or necessary.

An impossible being has an essence that precludes its existence. For example, a four-sided triangle is impossible in essence because triangles have three sides by definition — that is, triangles have three sides in essence.

Contingent things — like the horse or the human being — depend on something else for their existence. There can be a number of sufficient causes for contingent things to exist, the mother of a human being is just one example. As the philosopher put it, the contingent becomes “necessary” due to what is other than itself. All things in the cosmos of things, according to Ibn Sina, are contingent.

There must be something which has an essence that guarantees its existence in order to cause everything else. That makes it a “necessary existent” — it must exist by necessity. The necessary is the source of its own existence, it therefore eternally exists.

Look around you. See the things around you. These things could potentially not exist. If everything around us has a cause, what is the cause of all things, taken as a whole?

This aggregate of contingent things, the known cosmos, must be contingent itself. Reasoning would tell us that all things must be caused by something that is not caused, or self-caused. If that is not the case then the cause, by essence, would be included in the aggregate of caused things.

Some would argue that the aggregate of all things is distinct from all things taken individually. A machine, as a whole, is distinct from its parts, after all — it is a set that is different from the sum of its parts. Perhaps the universe as a kind of “set” is distinct from its parts.

That idea still posits a necessary existent, which is the universe itself. But the philosopher insists that the necessary existent must have unique properties that make it distinct from the cosmos of things.

This leads to the next part of Ibn Sina’s case for the existence of God. From the necessity of God, the philosopher maintains, we can understand the essence of God.

A necessary existent would be wholly necessary — it would be unique, simple, unified and immaterial. These are the divine attributes of God that we know from the concept of Tawhid.

There can only be one necessary existent. If we supposed that there were two, as an example, there would have to be a difference between them. A necessary existent would be necessary through and through, and the difference required to distinguish two Gods would have to be caused. Therefore, by reason, Ibn Sina rules out the idea that there can be more than one God. So God, as the necessary existent, must in essence be unique.

By the same reasoning it must also be simple, since if it had parts, those parts would need to be caused to be different from one another — since difference itself is caused. Nothing caused can be necessary, and so the necessary existent is superlatively simple, singular and unified.

We know that all material things in essence have parts. Things are made up of particles, they have colours, textures and shapes. A necessary existent could have no properties as such and no parts, since all these are also caused. And so God must be removed from matter, God must be immaterial and a pure intellect.

For Ibn Sina, there’s nothing we can understand about God that we cannot understand by reason. It’s an alluring and powerful idea, that we can know God through reason as much as faith.

The philosopher’s purely rational explanation for God is both popular and controversial. While the philosopher claimed that The Proof of the Truthful was fully commensurate with God as described in the Quran, many scholars and philosophers criticised the argument.

The case for The Proof of the Truthful gives God no free will, for example. A necessary God seemingly has no choice but to maintain the universe’s existence. Such a lack of agency and power would surely contradict the idea that God is all-powerful and absolutely just.

Ibn Sina’s Neoplatonist influences run deep into the idea of his necessary existent, and the philosopher’s ideas come close to the Platonist idea of “The One” or “The Good” — the fountainhead of being that precedes the pantheon of the Greco-Roman gods. This made many of his monotheistic commentators uncomfortable. The school of thought that Ibn Sina had founded was criticised by the influential theologian Ibn al-Malahimi for being corrupted by the abstract thought of Ancient Greece. Such ideas, the scholar asserted, stay from the prophetic character of Islam.

But it could be said that it is not so much abstract thought as self-reflection. Empirical reason is at the heart of the philosopher’s Proof of the Truthful — our existence is simply known and cannot be doubted. This axiomatic fact is the first building block of a vast and intricate system, its purpose to “heal” ignorance and rejoice in our understanding of God.

The necessary existent is an articulation of the human intuition of faith, and seeks the basis for that intuition — the divine.