Any proper discussion of causation needs to invoke the 18th-century Scottish philosopher, David Hume (1711 to 1776), and what has come to be called “Hume’s problem of induction.” Ideas expressed in An Inquiry Concerning Human Understanding (1748) over 250 years ago have relevance for today’s marketers. Let’s first examine the problem of induction from a general perspective, and then investigate its application to marketing.
Generally, the problem of induction states that there is no justification to believe that the patterns historically observed will continue into the future. This may seem to be a ridiculous proposition since we all believe that the sun will rise tomorrow, balls drop to the ground, and hot air rises. However, Hume contends that what we observe in nature is one thing following another—what is sometimes called constant conjunction. We attribute causation to patterns we observe because of our psychological disposition to do so—it helps us to make order of things.
The key to understanding Hume’s point-of-view is to appreciate the use of the term, justification, and to accept the fact that, in many situations, Hume is indeed correct. Often, we are not justified in assuming one event will follow another. For example, I am not an automotive engineer and, consequently, I have no good justification to believe that my car will start the next time I turn the ignition key, simply because it has always done so in the past. This is circular logic because the premise of my argument, “my car always starts,” assumes the truth of my conclusion, “therefore, my car will start in the future.” I may indeed be correct, but I have not given a good reason to support my conclusion.
Many businesses stick to the same old business models (i.e., “arguments”), believing that what worked yesterday will work tomorrow—Kodak, AOL, General Motors, Borders Books, Merrill Lynch, Montgomery Ward, and the list goes on. In marketing, however, generally what has worked in the past does not work indefinitely into the future.
What, then, can critical thinkers learn from David Hume? Do not assume that historical patterns will repeat themselves unless you have good evidence supporting that claim. In short, avoid the following kind of logic in an argument:
X happened historically
Therefore, X will happen tomorrow.
If you think that X will happen tomorrow, find some basis for this claim. For example, if X is your company’s recent historical growth rate, perhaps X is theoretically related to your country’s population growth rate. Linking X to an authority’s predicted population growth rate then gives you some grounds for saying that some level of X is likely to happen in the future.
Remember: Just because something happens with some historical frequency is not sufficient justification to say that it will continue to do so in the future.