Professor Robert Pasnau (University of Colorado)
'After Certainty: A History of our Epistemic Ideals and Illusions'
Professor Robert Pasnau (University of Colorado) delivered the Isaiah Berlin Lectures on Tuesdays of weeks 3-8 of Trinity Term at 5 pm on the following days, in the Lecture Room at the Faculty of Philosophy, Radcliffe Humanities Building (Woodstock Road, Oxford OX2 6GG).
Lecture 1 (13th May) - The Ideal
No area of philosophy is more disconnected from its past than epistemology. It is, indeed, only recently that epistemology has been recognized as a distinct field within philosophy. Rather than seek a precise analysis of anything in the vicinity of what we call “knowledge,” philosophers have historically been much more interested in articulating an idealized epistemology: an account of what it would be to have an ideal cognitive grasp of some part of reality, an ideal calibrated against what is possible for beings such as us, in a world such as this. For most of philosophy’s early history, this ideal was understood in terms of Aristotle’s Posterior Analytics, as the quest for demonstrative certainty grounded in the essences of things. But when that theory of essence comes into doubt in the seventeenth century, new conceptions of the epistemic ideal likewise arise, and a distinction emerges between the concept of knowledge and the concept of science.
Lecture 2 (20th May) - Certainty and Doubt
From antiquity through the Middle Ages and, most prominently of all, in Descartes, philosophers have pursued the epistemic ideal of certainty. It is not – as is so often said – that they took knowledge to require certainty, but rather that they regarded certainty as a crucial part of the epistemic ideal to which human beings should aspire. But beginning in the later Middle Ages, and even more in the seventeenth century, widespread doubts arose over whether certainty should be regarded as a part of the epistemic ideal achievable by us. Accordingly, in place of certainty, philosophers began to focus on probability, and began to articulate a new ideal: that we proportion our beliefs to the evidence. Out of this arises the concept of knowledge in something like our modern sense.
Lecture 3 (27th May) - The Sensory Domain
Pre-philosophically, it is often supposed that the cognitive ideal for beings such as us is to perceive a thing ourselves, directly. Philosophy from the beginning has directed much of its energies against this sort of naïve faith in sensation. Yet, even so, there has long been an abiding conviction among philosophers that there must be some domain where the senses get things right. Among Aristotelians, it was said to be the proper sensible qualities of things – color, sound, odor, flavor, heat – where the senses could be trusted not to err. In the seventeenth century, this doctrine was turned on its head, and those qualities now became the place where the senses most thoroughly lead us astray. At this point it becomes the so-called primary qualities – shape, size, motion – that the senses are best suited to perceive. Yet soon enough doubts arise even here, and philosophers begin to take recourse in the idea that what we perceive of the world are mere powers of bodies, powers that we can describe only as the things that cause us to have sensation. The character of the world itself begins to look quite inaccessible to sensory perception.
Lecture 4 (3rd June) - Illusions and Ideas
In place of a privileged access to the external world, seventeenth-century authors famously took the immediate objects of perception to be our own ideas. Although much attention has been given to the consequences of this doctrine, little has been said about its origins. There is a puzzle, in particular, about why philosophers began to talk this way, whereas for virtually the entire prior history of philosophy it was regarded as manifestly absurd to treat the objects of perception as inner sensory states. After canvassing and rejecting various alternative suggestions about what changed in the seventeenth century, I argue that what makes the difference is the increasing conviction that there are no suitable external objects for perception. So, if we see anything at all, the best candidates are not features of the external world, but features of our own mind.
Lecture 5 (10th June) - The Privileged Now
The final refuge of epistemic privilege – the one domain where our cognitive situation can seem to be at all ideal – might seem to be the self. Yet our privileged grasp of the self turns out to be a privileged grasp of the self right now – once it slips into the past, the privilege looks to disappear. So inasmuch as we seek to achieve the ideal, we need to consider just how many thoughts we can grasp all at once. Although such questions are not terribly familiar today, there is a long historical debate over the importance of grasping a whole argument all at once. In Descartes, in fact, such a possibility turns out to be critical to the method of the Meditations. Ultimately, however, there is reason to doubt whether we should privilege the present self in the way many philosophers have historically supposed.
Lecture 6 (17th June) - Skepticism and Hope
If our epistemic condition is sufficiently non-ideal, then the consequence may seem to be skepticism. Of course, if there is an all-powerful deity, then just as that being might deceive, so such a being might protect us from deception. But there is reason to wonder whether even an all-powerful deity could itself be completely confident of having knowledge. For even supposing that such a being cannot, by definition, be deceived, still there is a question of how can such a being know that it is such a being. This raises a more general question about whether the gap between how things seem and how they are is more than just an unfortunate feature of the human condition. Perhaps it is a logical feature of cognition in general that no evidence can ultimately be decisive in establishing any conclusion. If this were so, then the only alternative to skeptical suspension of belief might be an attitude of faith. Or, instead of faith, we might choose merely to hope, and so believe without pretending to have faith.