“There are no miracles!” David Hume, one of the greatest thinkers of Scottish Enlightenment, would say. His uncompromisingly sceptical philosophy was directed against claims of religion and metaphysics. But in more down-to-earth matters, it can also be very useful.


For a Scotsman, the basis of our knowledge is experience. But what does it actually mean? Some people have “experienced” encounters with aliens, so it is difficult to believe everything that experiences might suggests. The philosopher has made a meticulous criticism of what we can really say on the basis of data collected in this way. This approach alone is worthy of recognition nowadays when we are constantly bombarded with new data.


Hume believed that what we can be sure of are only facts passively perceived by our senses (as e.g. I see a computer in front of me) and relations between ideas that are obvious (2+2 = 4, the triangle has three angles, etc.).


Such conclusions are very conservative. For example, we can’t say that pulling the trigger caused the shotgun to fire. All we can say is that first, we saw the trigger being pulled and then we heard the gunshot. The cause-effect relationship alone is impossible on the basis of empirical observation.


In a slightly less radical form, the principle of “correlation is not the same as dependence” is still used in various studies today. A great danger for every researcher, from a doctor to a stock market analyst, is that the co-existing phenomena are too hastily recognized as interdependent. For example, very often giants are shown as an example which should be imitate. Sometimes literally. But the fact that Steve Jobs has been a black golfer and has been very successful doesn’t mean that anyone who changes his jacket or sweatshirt to black golf will soon become the owner of another Apple…


According to the Scottish philosopher, the thing that makes us see cause and effect relationships is the habit that event A is always followed by B. But that doesn’t mean it has to be that way!


Due to Hume, most of the “knowledge” that we use on a daily basis is by its very nature uncertain and is the result of mental habits, that we practise because of the necessity. However, if one cannot be sure of the truth of certain events, it is not wise to treat them as unquestionable dogmas.


Many people who revolutionized an industry did so precisely because they were able to distance themselves from the beliefs that everyone held. When in the nineteenth century it was “known” that further development would cause a shortage of oats for horses and thought about how to remedy this shortage, some looked from a distance at the eternal principles of the transport industry and invented the railway and then the car. It turned out that the “truth” that transport couldn’t do without horses was, in fact, an illusion.


It is not possible to conclude “what should be” from “what is” – is the most popular summary of a concept that has been called “Hume’s guillotine” by 20th century researchers.


Especially in the last century, it has provoked a serious discussion among ethics. What we should do and how we should behave is not a fact, nor is it a mathematical relationship, so we are unable to take it for sure. Yes, we can talk about what others think is right, but it is a different matter than what is really right. 


While in ethics, whether or not we consider Hume’s guillotine principle to be the right one is at stake, in professional work it is a great approach to freeing one’s creativity from the fetters of established customs in the industry. The awareness that “how you do it” is only a customary practice that can turn out to be wrong in the right conditions, makes it much easier for us to challenge it.


However, it’s important to remember that Hume wasn’t a total skeptic. 


He didn’t fall into nihilism and didn’t reject common sense in everyday life. His philosophy had a practical spirit and wasn’t to reject popular beliefs but to treat them with distance and know when to give them up.