Philip Clapson

Associate Research Fellow



The Theory of Brain-Sign

It is normal to assume consciousness exists. We take ourselves to be in the world because we can see and feel and think. The problem is, science has no explanation for this. How can the physical brain generate states of mental knowledge? Matthew Cobb expounds this well in his recent book: The Idea of the Brain: A History (2020).

However the project at Birkbeck alters the situation fundamentally with the theory of brain-sign. Brain-sign replaces consciousness. Consciousness is prescientific, so searching for it in the brain is a mistake. Brain-sign, on the other hand, will benefit neuroscience because it has a precise biological function.

Brain-sign facilitates communication between organisms. It occurs in vertebrate creatures. Vertebrate brains, having evolved in size and complexity, can enable organisms to cooperate with each other in non-predetermined behaviour, i.e. where each responds to the other step by step to keep the interaction going. This evolved ability vastly extends the possibilities of collective action, which significantly contributes to survival.

Brain-sign is the brain’s interpretation of its immediate causal orientation towards the world. It is a neural sign. What is vital for action with others is that there are corresponding causal orientations, and brain-sign signifies this. So when we shake hands and pass gifts our brains signify the domain of that interactive process – hands reaching out, parcels exchanged. But the neural mechanism of this process is not apparent to us. ‘We’ suppose we see, and this is how we negotiate the world. But the process is ‘invisible’, for ‘we’ are part of the sign. Signs are biologically ubiquitous and intrinsically physical.

This does not mean humans cannot talk to each other using mentalist terms – the realm of psychology, psychiatry, sociology. For mind talk is how brains have explained themselves. We still say the sun rises in the morning though it is not how we would describe the situation in astronomical science. What has been projected onto the brain by psychology et al., is a colloquial vocabulary which obscures the science of neuroscience. This is made clear by brain-sign theory.

Since the nature of being human is changed the theory takes some effort to absorb. Various articles set out to explain it in more detail (see Publications BIROn).

Brain-sign website




Philip Clapson is the author of brain-sign theory. The idea was developed while he studied for an MA in the Philosophy of Psychology at King’s College, London (1997/8). The first publication was in 2001. By 2007, when pursuing a PhD in the Philosophy Department at the University of Durham, the text of the theory, as then developed, was written out at length. He joined Birkbeck Department of Psychological Sciences in 2012. Since then the theory has expanded in scope with publications, and conference presentations listed below. Dr Clapson lectures on consciousness and its status.


Conference presentations

(2019)  Models of Consciousness, University of Oxford

> Presentation: Consciousness and the Theory of Brain-Sign

(2018) Context, Cognition and Communication, Institute of Philosophy, University of Warsaw, Poland

>  Presentation: The Theory of Brain-Sign

(2017)  Philosophical Issues in Psychedelic Drug Use, Royal College of Psychiatrists, London

>  Psychiatry as Science: The Theory of Brain-Sign

(2016)  Agency, Causality and Free Will, Institute of Philosophy, Zagreb, Croatia

>  Brain-Sign Theory Changes the Subject

(2015) The Human Sciences after the Decade of the Brain, Johannes Gutenberg  University, Mainz, Germany

>  The Theory of Brain-Sign: A New Theory of the Brain.

(2011) Durham/Bergen Universities, Norway

>  How to Make Neurophilosophy Real