Mind, Body and Soul: The Alternative Ideas Most People Never Hear About (Part 2)

You cannot remember your best friend’s phone number. You do not need to. Your phone remembers it for you. You check your calendar to know where you are going tomorrow, and a photo to remember last summer.

So where exactly is your memory? In your head? In your pocket? Both?

That question sounds playful, but it is one of several serious ideas that break out of the familiar choice between ‘mind is brain’ and ‘mind is soul’. Part 1 of this series covered that main debate. This part explores the alternatives. Some are centuries old. Some were tested in laboratories last year. None of them requires any background to understand.

Most people assume matter is the basic stuff of the world, and minds are something rare and special that appear inside it. Idealists turn this upside down.

The Irish philosopher George Berkeley argued in his Principles of Human Knowledge (1710) that to exist is to be perceived. Everything you know about a table, its colour, shape and hardness, comes to you as experience. Berkeley asked what reason we have to believe in some extra, unexperienced ‘matter’ behind it all. What, then, keeps the table in existence when nobody is in the room? His answer was God, who perceives everything continuously.

A very different idealism developed in India. Advaita Vedanta, set out most fully by the philosopher Shankara around the eighth century, teaches that the true self, called atman, is identical with ultimate reality, called Brahman. Consciousness is not a property that some things have. It is the nature of reality itself. Our sense of being a separate individual is, on this view, a kind of illusion that arises from ignorance.

The Dutch philosopher Baruch Spinoza, in his Ethics, published after his death in 1677, offered a striking solution to Descartes’ puzzle. Mind and body do not interact, because they are not two things. A person’s body and that person’s mind are one and the same thing, understood in two different ways: once as something physical and once as something that thinks.

An everyday way to picture this is a piece of music. You can describe it as vibrations in the air, or as a melody you hear. These are not two different things that somehow interact. They are one event described in two ways.

In the late 19th and 20th centuries, the physicist Ernst Mach, the psychologist William James and the philosopher Bertrand Russell developed a related idea called neutral monism. They argued that reality is made of a basic stuff that is neither mental nor physical. Arranged one way, it makes up what we call a mind. Arranged another way, it makes up what we call matter. Critics say neutral monism tends to slide back into either physicalism or idealism, and that it is hard to say what the neutral stuff actually is.

The German philosopher Gottfried Leibniz accepted that mind and body are different, but he denied that they affect each other at all. Instead, he proposed a pre-established harmony. At creation, God set mind and body to run in perfect coordination, rather like two clocks set to show the same time without any connection between them.

Leibniz also gave one of the most memorable arguments against explaining the mind mechanically. In his Monadology (1714) he asked us to imagine a thinking machine enlarged to the size of a mill, so we could walk inside. We would find only parts pushing against one another. Nowhere would we find a perception. Many people feel the same intuition today when they look at diagrams of the brain.

The French philosopher Nicolas Malebranche went further with occasionalism. He argued that God is the only true cause of anything. When you decide to raise your arm and it rises, your decision does not cause the movement. It is the occasion on which God moves your arm. Few people hold these views today, but they show how seriously great thinkers took the interaction problem.

What if your mind is real, but does nothing? Epiphenomenalism says the brain causes conscious experiences, but those experiences have no effect on anything physical, including your behaviour.

In 1874, the biologist Thomas Huxley compared consciousness to the steam whistle on a train. The whistle is produced by the engine, but it contributes nothing to moving the train forward.

The objections are strong. If your thoughts cause nothing, how could you ever write or speak about them, including about epiphenomenalism? And if consciousness has no effects, why would evolution have produced it? Even so, the view survives because it offers a way to accept both that experience is special and that physics explains every bodily movement.

A single water molecule is not wet. A single ant cannot build a nest. Yet many water molecules are wet, and an ant colony builds remarkable structures. This is emergence: wholes having features their parts do not.

In The Mind and Its Place in Nature (1925), the Cambridge philosopher C. D. Broad argued that the mind might be an emergent feature of the brain. It would depend completely on the brain, yet could not even in principle be predicted from knowing its parts.

Philosophers distinguish two kinds. Weak emergence is compatible with physicalism: the whole is fully explained by its parts, even if it is useful to describe it at a higher level. Strong emergence says something genuinely new appears, with its own powers. The philosopher Jaegwon Kim argued that strong emergence faces a problem: if the brain already causes everything the body does, there is no work left for an emergent mind to do.

A growing group of thinkers argue that the mind is not just what happens inside the head. This idea comes in several forms.

Critics argue that a tool being connected to your thinking does not make it part of your thinking, any more than your fork is part of your digestion. Supporters reply that in a world of smartphones, the line between your mind and your tools is already blurring. That is why the question in this guide’s opening is not entirely playful.

In a 1989 paper in the journal Mind, the philosopher Colin McGinn asked a provocative question: can we solve the mind-body problem? His answer was probably not.

McGinn argued that some property of the brain does produce consciousness, so there is nothing magical going on. But human minds may be ‘cognitively closed’ to it. Our ways of forming concepts may simply be unable to grasp it, in the way a dog’s mind is closed to algebra. The mystery would be a fact about our limits, not about the world.

Critics call this defeatist, and point out that many past mysteries, such as the nature of life, were eventually solved. Supporters reply that it is honest: no species should assume it can understand everything.

The mind-body question is not only a European one. Two further ideas from outside the Western mainstream offer fresh angles.

The Persian philosopher Ibn Sina, known in Europe as Avicenna, who lived around 970 to 1037, proposed the ‘floating man’ thought experiment in his great work The Cure. Imagine a person created fully grown, floating in the air, cut off from every sensation, unable to see, hear or even feel their own body. Would that person still know that they exist? Avicenna argued yes. Self-awareness does not depend on the body or the senses, so, he concluded, the soul is something distinct from the body. Readers often notice how closely this anticipates Descartes, around six centuries earlier.

The Indian school of Samkhya offers a surprising twist on dualism. It divides reality into consciousness, called purusha, and nature or matter, called prakriti. What is unusual is where it puts the mind. Thinking, ego and the senses all belong to matter. Only pure awareness belongs to consciousness. On this view, your thoughts are physical processes, but the light of awareness in which they appear is not. Some modern readers see a parallel with the hard problem discussed in Part 1.

In recent decades, neuroscientists have built theories of consciousness that can be tested. Two lead the field.

In 2025, the journal Nature published the results of an unusual experiment. Supporters of both theories agreed in advance on predictions that would count against each. A group of researchers called the Cogitate Consortium then tested 256 people across seven laboratories, using three kinds of brain scanning.

The results were humbling for both sides. Integrated Information Theory predicted lasting synchronised activity at the back of the brain during conscious experience, and this was not found. Global Workspace Theory predicted a burst of activity in the front of the brain when an experience ends, and this could not be confirmed either. Neither theory was proven wrong, but both need rethinking.

That outcome is good news in one sense. It shows that questions once left entirely to philosophers can now be partly tested in the laboratory.

Should these alternatives be taken seriously, or are they curiosities? Here is the best case each way.

The honest position is that the question remains open. These ideas are not settled answers. They are well-argued options, each with real strengths and real costs.

You do not have to pick a side tonight. Philosophers have argued about this for thousands of years, and the scientists have only just joined in. Next time you reach for your phone to remember something, or wake from a dream and wonder where you were, notice that you are living inside the question. That is reason enough to keep exploring it.

This content is for general information only and does not constitute legal, financial, medical or professional advice. It describes philosophical, religious and scientific positions for educational purposes and does not endorse or reject any religious or personal belief.