How can you trust that the floor that you stand upon every day does not crumble from beneath your feet? How can you feel sure that the engineers and architects are justified in their arrangement of your floorboards, patios, and walkways? If you can’t feel such a way, you’re in good company with one of the greatest enlightenment thinkers ever.

In his works on epistemology and his general theory of knowledge David Hume tackles this very problem, it is called the problem of induction.

For starters, induction is a form of reasoning that results in the inference of a general law from the observation of many particular but recurring instances. It is the backbone of experimentation and science as a whole. It has allowed humans to formulate the laws of nature and to live practically, but Hume says we have no rational grounds for asserting facts about our world from induction.

Limited In Nature

Induction is a system of reason that crucially allows us to make sense of the world around us, but it can’t provide a sense of what Hume refers to as necessary connection. Necessary connection is an impression that supplies us with the sense that one event always causes another. It is crucial to Hume’s work on causation, but we will explore it in depth in another post.

This absence of necessary connection essentially points out how nothing can be proved by science to occur 100% of the time. Although observed effects may have occurred every time, that doesn’t give us the grounds to believe that they will occur every time.

Mystery Bread

With induction, I can assume that when I consume bread, it will nourish me (because it has always done so thus far). But I cannot guarantee with a sense of reason or observation why it nourishes me. But let’s imagine that I do, in fact, understand that carbohydrates are a macromolecule, and that they are broken down within the body and digested to be turned into energy. 

Hume would ask me how I could be sure that that nutritional insight is the real cause of the bread’s nourishing effects? And if I dove further into the biochemistry of nutrient absorption and transit, I would be met with the same question. 

Following this chain of cause and effect leads to an infinite regress. And Hume highlights these points precisely to display the limits of human reason. The problem of induction is not so important because of its existence in the world. But in my opinion, it is our acceptance of it. It seems that such a monumental and foundational system of belief is centered around logical procession, but lacks the tools to allow for certainty.

The problem of induction doesn’t really matter to most people. Even Hume himself was unable to act in the world with the skepticism that he procured. The bread you eat today will nourish you, and the floor will not crumble underneath you; it probably never will. What does matter, though, is that we remember to be skeptical of things, search for justification, and stay open-minded. 

You never know when the rational grounds that you view the world from are lacking rationality.