I can think of no better way to draw our unit on the Age of Faith in Reason to a close than
by examining the philosophy of the great Immanuel Kant, who just as Thomas Aquinas can be viewed
as the the pinnacle of medieval philosophy, you can think of Kant as being the pinnacle
or the high watermark of the age of Enlightenment, of modern philosophy. You know, just as Thomas
Aquinas pulls together the disparate strands and different traditions and synthesizes them
in a very creative way, Immanuel Kant does the same thing with respect to his modern
forebears. So what I wanna do to make our way into Kant's philosophy is to give you
the sort of immediate backdrop, beginning with the 16th century philosopher René Descartes.
So remember this is at the the beginning of the scientific revolution, 1500s you see the
emergence of the new science, mechanism, and the displacement of the old Aristotelian science,
and this brought with it a kind of a philosophical crisis because Aristotle's science was wedded
together with Aristotle's metaphysics. His metaphysics or first philosophy, his general
way of viewing the world was was tailor-made for his science. Once his science is is seen
to be falling apart, is is is being replaced with the new Newtonian mechanistic science,
the question then becomes: how can we formulate a new metaphysics to displace the Aristotelian
metaphysics and to secure or to support the new science? So this is the the project that
Descartes engages in in the Meditations and and in other works. His attempt, really, is
to become the new Aristotle, to develop and to deliver a new metaphysics that's gonna
support the new science, and as well to develop a new philosophical methodology, which would
lead to certainty and objective knowledge. Now, you know, through time the other rationalist
philosophers who followed Descartes also use this kind of Cartesian method and have many
of the same aims. You know, in addition to wanting to bolster and support the new science,
many of them also wanted to reconcile the new science with certain beliefs that seemed
to be jeopardized by the new science, ancient beliefs in, you know, the existence of God,
the freedom and rationality of the human person, the immortality of the soul, and so forth.
So Descartes and his followers take up this new philosophical methodology, which is supposed
to provide a foundation for the new science and reconcile it with these age-old beliefs.
The crisis that starts emerging towards the end of the modern period follows on the heels
of a kind of recognition that the project isn't working out as well as it it was hoped
by these rationalistic philosophers. I mean, one of the embarrassing things about it, is
that these philosophers engaged in the same kind of philosophical method, they use the
same method, which was supposedly to lead to objective knowledge, certainty to a disclosure
of the real nature of the world and so forth, and again and again they kept on disagreeing
with one another, coming up with very different metaphysics, different outlooks, using this
same method which is supposed to lead to a sort of geometrical certainty, to mathematical
certainty. In addition to that, the the disagreements led to a kind of new movement, which we came
across in the philosophy of Locke and Hume, a movement which was empiricist in its outlook,
in its orientation rather than rationalistic. Remember Locke says, no we don't have these
innate ideas that allow us to sort of penetrate into the depths of nature and to to see the
world and and all things as they truly are. Rather he he limits what we can know, he limits
the scope of of human knowledge by saying that rather than possessing innate concepts,
innate ideas all that we can know about the world or even think coherently about the world
or about anything else, comes to us from sense experience, comes to us through the senses.
Now you will recall that Locke himself is still a pretty conservative philosopher in
the sense that he too believes in God, believes in life after death, believes in freedom in
a in a certain compatabilistic sense of freedom and so forth. When we get to Hume, there's
a greater and greater degree of suspicion that the ability of the human mind to come
to knowledge of things like God, of things like the afterlife, is is it's it's not as
optimistic as the way that the earlier philosophers had viewed it. In fact there's a greater degree
of skepticism concerning not only, you know, the fundamental metaphysics and the the nature
of reality and so forth, but with Hume what you begin to see is a skepticism about even
our ordinary knowledge claims, even common claims concerning what we can know about the
future, say, that it's gonna be in conformity with the past, that the same laws of nature
will continue to govern things just as they have always done. That fundamental principle
that grounds our causal reasoning and our inductive logic and so forth comes under scrutiny
in Hume's philosophy and and reason itself, the ability of the mind to know anything other
than its own contents, its own immediate contents, becomes more and more narrow in its scope
in terms of what it can know. Now because of this, you see a really very interesting
track through from Descartes through Hume, and it's a sort of a downward track in a way,
it begins with this great estimation, this positive evaluation of the the ability of
the human mind to penetrate into reality to know things with certainty to know things
objectively, and it ends with a kind of skeptical pessimism with respect to what we can know.
And in fact Hume had such a pronounced influence at the end of the the modern period when Kant
begins to emerge, that it it it's really owing to David Hume in some ways that that we receive
the philosophy of Immanuel Kant. Kant memorably says that it's David Hume who awoke him from
his dogmatic slumber. It was this challenge, this skeptical challenge raised by Hume and
the sort of crisis of the Enlightenment raised by all of the disagreements and and the the
lack of certainty and so forth that that is the immediate challenge that Immanuel Kant
faces. So it's in this framework that we need to understand his his philosophical mission
and his work. So what does Kant say with respect to Hume's skeptical challenge? Remember Hume
had said we can't know not only things about the future that we commonly think that we
can predict about the future, but we we have to remain skeptical even about the existence
of ordinary objects in the external world. Kant says no, this is a deep problem, in fact
he says it's one of the greatest scandals of philosophy that nobody's been able to prove
the existence of the external world, you know, perhaps we're all just trapped in a realm
of ideas with nothing substantial underlying them. So, Kant wants to address this concern,
solve this problem, set philosophy on a secure footing, and because of this, you can see
him as having very conservative aims, right, at the same time the means that he deploys
in order to attain this aim or these these conservative goals are fairly radical means.
He undergoes what he himself calls a kind of Copernican revolution in philosophy. So
remember Copernicus had revolutionized astronomy by saying that, you know, look, instead of
of seeing the solar system as geocentric, we need to see it as heliocentric. So the
sun is the center of the solar system, and we orbit around it, and that, you know, forces
us to rethink our position in the solar system and forces us to recognize that the phenomena
which look geocentric also look heliocentric, right, if you put on those lenses instead,
okay. Well in what respect is Kant's philosophical revolution Copernican in its nature? Well
you can think of the traditional aim of metaphysics as being the attempt to get to know what reality
is really like in itself. We've got appearances, we've got the way things seem to us, the way
that we perceive things, the way we conceptualize, cognize things, and then there's the things
themselves. The question is always: well are our representations of reality accurately
displaying or representing what they seem to be representing? Do do they, do our appearances,
representations match up with the way that reality is in itself? Kant says, you know,
we need to think about the task of philosophy somewhat differently now. Instead of thinking
of the world, items in the world as existing out there objectively in themselves and then
wondering about the way that they appear to us, the extent to which they match up with
the appearances. Rather we should think of the items of empirical experience as being
in part constructed by our appearances. So what Kant says is, you know, when it comes
to the thing in itself, if we asked the question what is the thing in itself like. What's reality
in itself like? Well, what we're really asking is the question, what is reality uncognized
like? But of course any attempt to say what it's like will involve you in the very act
of cognizing it, right. I mean in order to think about something, you filter it through
your conceptual scheme, your categories of thought. Now we can have trust, we can be
sure that the future is gonna be conformable to the past with respect to the categories
of causation: space, time, and all of those, but we can do it, here's the price tag, only
if we consider those objects in the phenomenal or empirical world as being in part constituted
by our own conceptual categories of space, of time, of causation. So this leads to a
kind of constructive anti-realism on Kant's part. You know, you yourself by way of experiencing
and conceptualizing the items in your perceptual field, form, in part, constitute, in part,
what those items are, okay. So the items in your phenomenal experience are items of which
you can have some degree of certainty because you yourself cause them, in part, to be the
kinds of things that they are. Items outside or distinct from the phenomenal objects of
your experience Kant calls noumenal objects. These are things that exist in themselves,
but they're not objects of knowledge for us. So this is gonna sound somewhat similar to
to Plato's kind of dualistic theory of reality where you've got the realm of the forms and
you've got, you know, the the world of sense perception. The difference is, Kant doesn't
think we've got any a priori epistemic access to the realm of the forms. He is not thinking
of noumena as being forms in Plato's sense anyway. Noumenal objects are things as they
exist in themselves, and they exist in a a different realm or they're a different aspect
of reality, one to which we have no access. When it comes to the empirical knowledge we
possess of the world, that can be on a sure footing, but again the price tag, the the
way that it can be an item of knowledge and of certainty for us, is only because we ourselves
end up constructing the world of our experience.