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Why do people believe 9/11 was an inside job?

Quassim CassamThe reasons why some people believe bizarre conspiracy theories are set to be explored in a new project by a philosopher from the University of Warwick.

Professor Quassim Cassam has been awarded £250,000 by the Arts and Humanities Research Council (AHRC) to study what he calls ‘intellectual vices’. The title of his project is ‘Vice Epistemology’.

He believes his research could help to explain how certain claims – for example that 9/11 was masterminded by the US government – are able to gain so much traction.

His findings may also shed light on why some people are susceptible to becoming radicalised in ways that make them potential recruits for extremist organisations such as Islamic State.

Prof Cassam said: “In 2008, a global poll of over 16,000 people found fewer than half believed that al-Qaeda was responsible for the 9/11 attacks, with a significant number attributing the collapse of the World Trade Centre towers to a controlled demolition by the US government.

“We live in a world where strange conspiracy theories such as this abound, often with dire social and political consequences. But how are such beliefs to be explained?

“My project as an AHRC Leadership Fellow is about the possible role of intellectual vices in fuelling these beliefs. By intellectual vices I mean intellectual character traits such as gullibility, closed-mindedness, prejudice and dogmatism. What I call vice epistemology is the philosophical study of the nature and significance of such character traits.”

He added: “There are some true conspiracy theories, such as Watergate, but the philosophically interesting ones are those that are clearly false and refuted by best available evidence. Why is it that some people continue to believe such theories?

“One way of answering is to ask the person and they will give you their reasons, but the thing that’s striking is that these reasons will often be bad reasons. They have access to the evidence, but continue to subscribe to their theories. If you simply answer the question ‘why do they believe these things?’ by reference to the reasons they give you will have an incomplete account – you need to go deeper.

“The thing is that these people aren’t necessarily crazy or irrational but, as Harvard Law professor Cass Sunstein points out, crazy thoughts are often held by people who are not crazy at all. But if these people aren’t irrational, why is it and how is it they believe the things they believe? We need an alternative explanation.”

Prof Cassam’s study will also consider whether intellectual vices may explain why there is sometimes a gap between the results of scientific research and the implementation of those findings by practitioners on the ground. “This gap is a major challenge facing clinical and other human services, identified by the World Health Organization,” he said.

The research is due to begin in April 2016.

Notes to Editors:

Professor Quassim Cassam is available for interviews. Contact Lee Page, Communications Manager at The University of Warwick. Tel: +44 (0)2476 574 255. Mob: +44 (0)7920 531 221. Email:

The Arts and Humanities Research Council (AHRC) funds world-class, independent researchers in a wide range of subjects: ancient history, modern dance, archaeology, digital content, philosophy, English literature, design, the creative and performing arts, and much more. This financial year the AHRC will spend approximately £98m to fund research and postgraduate training in collaboration with a number of partners. The quality and range of research supported by this investment of public funds not only provides social and cultural benefits but also contributes to the economic success of the UK. For further information on the AHRC, please go to:


Lee Page

Communications Manager, University of Warwick

Tel: +44 (0)2476 574 255

Mob: +44 (0)7920 531 221