Immanuel Kant
The Enlightenment was a time of great political as well as philosophical change. Much was written about how society should be organised. Locke’s vision of a society that protects and promotes life, liberty and the pursuit of happiness was cemented in the US Declaration of Independence, and the culmination of the Enlightenment – the French Revolution, after which meritocracy trumped aristocracy in Europe.
Immanuel Kant (1724-1804) developed the predominant philosophical position of the modern era. David Hume had pointed out that induction couldn’t prove anything – it was just a best guess. If you drop an apple a million times and a million times it falls to the ground, that was not enough proof for Hume that it would fall to the ground the million-and-first time it was dropped. And why should it? We’re just making a guess based on our experience. We formulate a ‘law’, such as gravity, but we don’t know what causes it – just that in human history at least, it’s always done the same thing. Kant agreed with Hume about induction, but he also believed that Newton had discovered real truths, using induction. How could those two positions be reconciled?
Kant said that the mind doesn’t passively receive sense-data. All information that we receive about the world is channelled through the matrix of the mind. We can never experience the world as it is (Kant called this the noumenal world), only as our mind organises it for us (Kant called this the phenomenal world). Empiricism ‘works’ because it relates to our minds’ interpretation of the universe, of existence.
The concepts of space and time, for example, are a priori for humans. Our experiences are projected onto our already existing concept of space and time, given to us by our mind. So the ‘laws’ we discover and develop by observing nature correlate to the laws of our pre-existing mental structure; and mathematics works in that structure, because maths presupposes a context of space and time. But space and time for humans don’t exist separately from human mental structures, which are a priori – we’re born with them. We can observe objects in space and time, but we can’t observe space and time themselves – they’re just the a priori context for all our experiences and our rational thoughts. When looked at this way, empiricism and rationalism are reconciled, and it’s why mathematics so perfectly describes our experiences of the external world.
Kant’s approach, known as transcendental idealism, began to shake the foundations of human knowledge. We can have some knowledge of the world – but only the phenomenal world, which is real enough. The noumenal world is beyond us, however. Kant was the first modern philosopher to see the world as some sort of construct – the mind as a matrix that we can never be sure we can trust. This sowed the seeds for a much-later postmodernist, relativist way of thinking. But the basic idea is an old one. There is a Talmudic saying, for example: ‘we don’t see things as they are, we see things as we are’.
Current work in quantum physics seems to substantiate the idea that humans can’t know the true essence of things. The more we learn, the more bewildering the universe becomes. But ultimately, transcendental idealism affirms our humanity, and rejects both radical scepticism (because humans can know what humans can know, from a human perspective), and the arrogant claims of metaphysicians that they can somehow lift the veil on ultimate reality (because humans can only know what humans can know – which doesn’t include ultimate reality). And so a simple conclusion we can draw from Kant, I think, is that we can’t understand the world by experiencing alone, or by thinking alone, but by a combination of the two – which somehow feels right.
Mary Wollstonecraft Shelley
Kant provided a fitting culmination to the Enlightenment, after which it was assumed that humanity would enter a new world illuminated by science. This wasn’t an assumption shared by the Romantics however, because they feared the technology that science made possible. Frankenstein by Mary Shelley (1797-1851) is one of the most famous expositions of this. It’s not difficult to see their point – it does appear that our technology is more advanced than our ability to use it wisely. Nowadays, most scientists are employed to develop money-making technology rather than to further human understanding – but it’s not a reason to fear the accumulation of knowledge itself. Surely understanding is better than ignorance? We can still protect and appreciate nature, if we design and build better political systems.