Shortly after our walk began, Nancy noticed an elegant old doorway which drew us near. At the time, we had been marvelling at the narrow alleyways, cobblestone roads, and ornate old buildings; this doorway (shown below) was another amazing sight on our walking tour.
However, a plaque by the doorway heightened our interest in it. This was the location of the house in which philosopher Rene Descartes lived in the final year of his life. Descartes had come to Stockholm in 1649 to be the philosophical mentor of Queen Christina. However, to fit her schedule, Descartes (a notorious late riser) found himself walking from here to the palace (a few minutes away) for 5 am philosophical discussions. The chilly walk, and cold castle, led to pneumonia which killed Descartes in 1650, only a few months after his arrival in Sweden. (An alternative theory provided by Cartesian scholar Theodor Ebert is that Descartes was poisoned by a Catholic priest who used a communion wafer laced with arsenic.)
This surprising plaque provided a delightful historical context for our walk – Descartes lived here! – but, later, made me reflect upon Descartes’ impact on cognitive science in general, and on my own training in particular.
Classical cognitive science, which views cognition as the rule-governed manipulation of symbols, is largely the modern face of Cartesian philosophy. Descartes’ view that one acquires new knowledge via reasoning from axiomatic knowledge is completely consistent with the classical view that cognition is computation. In my new book (which will be released within the next few weeks), I suggest that the critical difference between classical cognitive science and Cartesian philosophy is that the former replaces the latter’s dualism with materialism.
As a PhD student I was steeped in the classical approach while being trained in the fabulous environment created by my supervisor, Zenon Pylyshyn. My thesis concerned computational vision, and I spent a fair amount of time working through mathematical proofs concerning natural constraints that could be used to solve certain problems facing human motion perception. Such computational investigations are clearly consistent with the spirit of Cartesian philosophy.
When I arrived at the University of Alberta in 1987, I was faced with the task of developing my own research program. To pay the bills, I continued with some work on computational vision. However, I also began to steep myself in connectionist cognitive science, primarily with the goal of critiquing it. To my surprise, I made a handful of discoveries that made me more sympathetic to it. In some sense, I was replacing the influence of Rene Descartes with that of John Locke! Later work on interpreting artificial neural networks permitted me to flesh out some key similarities between classical and connectionist cognitive science, similarities that served as the foundation of my first book. Artificial neural networks are involved in the majority of my publications; they reflect an empiricist philosophy that is difficult to reconcile with Cartesian rationality. Interestingly, though, I am reluctant to think of myself as a connectionist.
More recently I have become very interested in the central ideas of another school, embodied cognitive science. In terms of the era of Descartes and Locke, embodied cognitive science has roots in the philosophy of Giambattista Vico. My students and I explored embodied cognitive science using some simple LEGO robots. One result of this has been my openness to considering the virtues of situation and embodiment.
It would seem that my development as a cognitive scientist has taken me a long distance from my classical training; the phrase “Descartes lived here” describes the evolution of my own beliefs about cognitive science.
However, I have not completely abandoned my classical roots. I still see a great deal of merit in the core assumptions of classical cognitive science. My soon-to-be released book makes an effort to find links amongst the foundations of classical, connectionist, and embodied cognitive science. I argue that these three approaches are not as incommensurable as one might imagine. To the extent that my personal cognitive science can be represented as the cobblestone alleys of Gamla Stan, Descartes still walks there – perhaps softly.