What Odors and the Olfactory System Suggest

You encounter different smells at every moment of our lives, such that it might even be said that we live in a world of aromas, surrounded by smells from flowers, trees, foodstuffs, animals, industrial products, bacterial decay, and other human beings.

When we look at this world, made up of thousands of kinds of aromas, a rather striking equilibrium and harmony emerges: We like the smells of substances beneficial to us, and are repelled by those of harmful substances.

The smells of foodstuffs useful to the body awaken a feeling of pleasure in us, and lead us to feel hunger for them. The smell of food cooking when we are hungry encourages us to eat, and along with taking pleasure from eating, we nourish our bodies at the same time. When our bodies are busy digesting, on the other hand, and we feel no need to eat any more, then the smell of food will not seem so attractive.

Those smells we describe as unpleasant, on the other hand, are generally substances harmful to us. We can easily identify poisonous chemicals by their smell. The unbearable stench given off by rotten fruit or meat—unpleasant odors that arise as a result of bacterial activity—warn us to stay away from them.

It’s beyond dispute that this reaction to scents is of vital importance to human health. As a general rule, dangerous or harmful substances can immediately be distinguished by their noxious smells. Parsley, for example, bears a close physical resemblance to the poisonous plant hemlock, yet their smells are completely different. Parsley has a pleasant smell of its own, whereas hemlock’s is very repellent. Were it not for this system, we might eat hemlock assuming it was parsley, or drink a harmful chemical concoction thinking it was fruit juice. We would live our whole lives in the danger of being poisoned and, as a precaution, would have to carry around lists of what was harmful or not.

Although parsley and hemlock (right) are plants that resemble each other very closely in terms of appearance, parsley is useful and sweet-smelling, while hemlock is poisonous and smells unpleasant.

The delicate balances seen everywhere in the universe also manifest themselves in the olfactory system. The scent-perception capacity of every living thing has been regulated in the light of the environment in which it exists and to best meet its needs. Consider human beings. If our scent-perception capability were less than it is, we might not be able to recognize dangerous situations. If our capacity were as keen as a dog’s, however, then we would constantly be distracted and ill at ease, bombarded by too many stimuli.

The balances in question can also be seen in the structures of scent molecules. For example we do not like a concentrated aroma that we normally like in lower concentrations. Even though the aroma of flowers in a garden is most attractive, a concentrated essence made from those same plants is not. This indicates that these have been created in the ideal proportions for human beings.

As a mercy from God, foods that benefit the body have pleasant smells.

It is clear that every detail to do with smell has been specially created for human life and is a blessing from God.

To understand the scale of that blessing, imagine that the system was the exact opposite of what it actually is. A great many foodstuffs of vital importance to us might possess unpleasant or even revolting smells. Imagine if water smelled like gasoline, bread like rotting meat, or cheese like rotten fruit. No matter how hungry or thirsty you might be, it would be a real torment to eat or drink these substances. Even eating a favorite meal would become unbearable because of its disgusting smells.

To the heedless, the odors we’ve lived with since birth might appear to be natural and spontaneously occurring. But if you reflect on the details set out above, you will comprehend the manifest truth: It is God, the Compassionate and Merciful, Who creates the foods and plants we need, together with their attractive smells. Our Lord, the infinitely Pure and Provident, has created our sense perception in line with our comfort, as is the case with all the systems in our bodies.

As a mercy from God, foods that benefit the body have pleasant smells.

With His compassion and affection, He has caused us to like beneficial things and abhor harmful ones as unpleasant. Our duty is to reflect on the fact that God has created and blessed us with the pleasant scents we perceive, and to give thanks. Those who behave in such a way will, if God so wishes, attain the Heaven where they will encounter the true originals of such blessings. Those who deny God’s blessings and are ungrateful will, on the other hand, find a mixture of pus and blood, thorns and boiling water specially prepared for them in Hell. These are divine promises revealed in the Qur’an, and are absolutely sure to come to pass.

What Odors Stemming from the Human Body Bring to Mind

Unless they take precautionary measures, if people go hungry for even a short period of time, unpleasant odors can arise from their bodies when they walk at a fast pace, climb stairs, or move about during their daily lives. Even if they do not move about much, every part from their hair to their feet will soon become dirty and lead to unpleasant smells unless they bathe and groom themselves. Just as there is a specific purpose behind the creation of everything in the universe, so there is considerable in wisdom in the odors that arise from the human body.

If God so wished, He could have created our scent-perception system in such a way that we would not notice unpleasant smells, or else have created all aromas to seem attractive to human beings. In that case, what is His wisdom behind the creation of unpleasant odors?

Unpleasant smells remind people of their helplessness, and are also a means whereby we can better appreciate the value of beauty.

No doubt that they signal a weakness and a deficiency for human beings. Deficiencies of this sort in people's bodies are a means whereby they can reflect that they have been created to be imperfect, and that only God is free from all imperfection. They will better comprehend His greatness and their need of Him. No matter how well people may groom themselves, soon they will feel the need to clean themselves yet again. When bacteria too small to be seen with the naked eye go into action, unpleasant odors will again begin to form. This reminds us that the world is transient and flawed, but that the Hereafter is endless and perfect. It brings to mind the fact that there is no reparation for being taken in by this world's deceptions. It is a means of conceiving of Heaven, humanity's eternal home, where there are no unpleasant smells, and believers will be recreated. It also helps to remind us, by comparison, how unbearable will be the stenches specially prepared in Hell for the deniers.

Bad smells also remind us that human beings have no physical superiority about which to become proud or arrogant. Humans are helpless, and no matter how they may strive to eliminate that helplessness, they will never succeed. Even the most attractive actress, the most successful businessman, and the most intelligent scientist is faced by the exact same helplessness.

Roses, which emerge from the muddy earth and have no protection against wind, rain and dust, smell ineffably delightful. Sweet-smelling plants require no special cleaning, despite their remaining outside under all kinds of weather, because God has created them in an astonishing way, with a special creation. Indeed, when describing something that is beautiful, clean and well cared for, we often compare it to a flower. It is clear, therefore, how meaningless it is for anyone to be proud and arrogant.

It is He Who sends down water from the sky from which We bring forth growth of every kind, and from that We bring forth the green shoots and from them We bring forth close-packed seeds...(Surat al-An'am: 99)

In conclusion, for thinking people, even bad smells represent life-long lessons and reminders, like all the other proofs of creation in the millions of details in the universe. All you need is to reflect deeply upon them. In one verse, God reveals:

In the creation of the heavens and Earth, and the alternation of the night and day, and the ships which sail the seas to people's benefit, and the water which God sends down from the sky—by which He brings the earth to life when it was dead and scatters about in it creatures of every kind—and the varying direction of the winds, and the clouds subservient between heaven and Earth, there are Signs for people who use their intellect. (Surat al-Baqara: 164)

Flowers emerge from the soil and live amid dust, wind and rain, yet appear very clean and emit delightful aromas. But human beings, despite all the means at their disposal, have to wash very often.

Good Health in Scents

Aromas obtained from plant essences or oils have been used for therapeutic purposes for thousands of years. This technique is based on the fact that different scents produce different effects in people. Today, experiments performed using electroencephalography (EEG), which identify electrical signals inside the brain, have shown that certain odors can have desired effects on the brain.59 Smelling certain aromas sets into action some unidentified systems in the brain. As a result, developments affecting heartbeat, blood pressure, respiration, the memory, stress levels and certain hormones all take place.60

The aromas obtained from plants are used in the treatment of many diseases.

But how do plants know which aromas will benefit human health? How can they establish the most highly advanced laboratories to produce health-giving aromas inside their own tissues? How do they create aromatic scent molecules, capable of containing up to 500 different chemical substances and with exceedingly complex structures?61 How are they able to squeeze their pleasant aromas into the limits of a scent-perception system—which they are not acquainted with and whose functions they are unaware of—can perceive? How do they determine the ideal concentrations for human beings?

When the question is examined from the other side, we encounter these questions: How is the human sense of smell able to distinguish among the individual aromas of thousands of plants? How do scent-receptor cells without the slightest knowledge recognize molecules the first time they encounter them? How can unconscious proteins, cells and nerves establish extraordinarily complex systems among themselves to perceive dizzying aromas from the world of plants?

The answers are so plain as to leave no room for doubt: It is God, the Lord of the worlds, Who created the mechanisms that produce the flowers’ attractive aromas in great harmony, and Who created the scent-perception system that detects them, and Who gave plants their health-giving properties.

It is revealed in the Qur’an that sweet-smelling plants are a blessing:

He laid out the earth for all living creatures. In it are fruits and date-palms with covered spathes, and grains on leafy stems and fragrant herbs. So which of your Lord’s blessings do you both then deny? (Surat ar-Rahman: 10-13)

How people should behave in the face of the blessings they are given is revealed in another verse:

Say: "It is He Who brought you into being and gave you hearing, sight and hearts. What little thanks you show!" (Surat al-Mulk: 23)