Paul Thagard


Paul Richard Thagard is a Canadian philosopher who specializes in cognitive science, philosophy of mind, and the philosophy of science and medicine. Thagard is distinguished professor emeritus of philosophy at the University of Waterloo. He is a prolific writer, and has contributed to research in analogy and creativity, inference, cognition in the history of science, and the role of emotion in cognition.
In the philosophy of science, Thagard is enormously well cited for his work on the use of computational models in explaining conceptual revolutions. Perhaps his most distinctive contribution to the field is the concept of explanatory coherence, which he has applied to many historical cases. He is heavily influenced by pragmatists like C. S. Peirce, and has contributed to the refinement of the idea of inference to the best explanation.
In the philosophy of mind, he is known for his attempts to apply connectionist models of coherence to theories of human thought and action. He is also known for HOTCO, which was his attempt to create a computer model of cognition that incorporated emotions at a fundamental level.
In his general approach to philosophy, Thagard is sharply critical of analytic philosophy for being overly dependent upon intuitions as a source of evidence.

Biography

Thagard was born in Yorkton, Saskatchewan on September 28, 1950. He is a graduate of the Universities of Saskatchewan, Cambridge, Toronto and Michigan.
He was Chair of the Governing Board of the Cognitive Science Society , 1998–1999, and President of the Society for Machines and Mentality , 1997–1998. In 2013 he won a Canada Council Killam Prize, and in 1999 was elected a fellow of the Royal Society of Canada. In 2003, he received a University of Waterloo Award for Excellence in Research, and in 2005 he was named a University Research Chair.
Thagard was married to the psychologist Ziva Kunda. Kunda died in 2004.

Philosophical work

Explanatory coherence

Thagard has proposed that many cognitive functions, including perception, analogy, explanation, decision-making, planning etc., can be understood as a form of coherence computation.
Thagard put forth a particular formalization of the concept of coherence as a constraint satisfaction problem. The model posits that coherence operates over a set of representational elements which can either fit together or resist fitting together.
If two elements p and q cohere they are connected by a positive constraint, and if two elements and incohere they are connected by a negative constraint. Furthermore, constraints are weighted, i.e., for each constraint there is a positive weight.
According to Thagard, coherence maximization involves the partitioning of elements into accepted and rejected elements in such a way that maximum number of constraints is satisfied. Here a positive constraint is said to be satisfied if either both and are accepted or both and are rejected. A negative constraint is satisfied if one element is accepted, and the other rejected.

Philosophy of science

There has been some decrease in interest in the demarcation problem in recent years. Part of the problem is that many suspect that it is an intractable problem, since so many previous attempts have come up short. For example, many obvious examples of pseudoscience have been shown to be falsifiable, or verifiable, or revisable. Therefore, many of the previously proposed demarcation criteria have not been judged as particularly reliable.
Thagard has proposed another set of principles to try to overcome these difficulties. According to Thagard's method, a theory is not scientific if:

Major works

Thagard is the author/co-author of 13 books and over 200 articles.
And co-author of:
He is also editor of: