David Hume is an 18th century philosopher who was one of the main philosophers arguing against rationalism and for empiricism. During this time there was a whole debate between the rationalists, who thought that our knowledge of things came from innate ideas (philosophers like Descartes, Spinoza and Leibniz) against the empiricists who thought that knowledge comes only from our senses (philosophers like Locke, Berkeley and Hume). You could see this as an intellectual war between two very different camps, who would then be united by our good friend Immanuel Kant.
But we’re here to talk about Hume and Hume was an empiricist, a pretty radical one at that. In this book he tries to convey his view of epistemological (study of knowledge) questions. In this book he says that people are not born with ideas. He gives the example of Adam. Being just created by God, Adam cannot know that water would drown him if he would put his head underwater because no one has ever seen this happen (since Adam is the first human). The only knowledge we can get is from impressions of the world and because they work by cause and effect. Only because I have felt myself drowning or have seen others do it, do I believe that water will drown me. It’s the same with a ball. If I have never seen someone kick a ball, I couldn’t infer what the ball would do. In my eyes (those who have never seen a ball being kicked) the ball could do anything; it could for all I know just float up.
Hume starts off with this basic principle, that everything has a cause. In this way he is a determinist. Something can only happen if it has a cause. But he was also a compatibilist which means that even though you are determined, you have a free will. You are just limited in your freedom. Hume declares that being determined is a prerequisite to have a morality. It is because we want criminals to better their lives that we have prisons and a judicial system. If we thought that that could not change someone, why would we invest in it?
To infer what the effect will be from the cause is determined by probability. Since we use induction (meaning inferring from many individual claims a general claim) there might still be mistakes we make. It is totally possible in an inductive reasoning that all the premises are right, and the conclusion is wrong. This is not the case with deduction (meaning going from a general claim to individual claims), which the rationalists try to use. Thus, we use probability to determine if something will happen. When I kick a ball it has a high probability that it will bounce away, but who knows, maybe it does something else.
Further in the book he tries to offer responses to many different topics while using his basic system of epistemology. He argues that those who believe in miracles cannot be rational and that miracles can never be proven and thus we must cast them away. He also responds to the sceptics, those who doubt everything (like Descartes famously did). Sceptic philosophy amounts to nothing accept showing us that we are not always right, according to Hume. It is always fun to see a great philosopher trying to undermine another great philosopher’s work.
The book itself is quite hard to read. I had to read some paragraphs many times before I finally understood his argument or claim. Yet Hume is extremely easy to follow. His arguments and reasoning follow a straight line and even the smallest of details he tries to point out. So, if you understand his argument in the first paragraph it will be so much easier to understand his next claim in the second paragraph. In this way there is room for little ambiguity.
I would highly recommend this book to anyone who knows already some things about Hume’s theses. If you haven’t read Hume, you should read a quick introductory (Wikipedia is fine). This will save you a lot of time while reading this book, so you don’t have to read every paragraph ten times. If you are a rationalist, pick up this book to try and come up with answers to his questions. If you’re an empiricist, pick up this book to strengthen your arguments. If you are neither, just also pick up this book. This book is not one of those one should cast away into the flames.