Is there anything in your life about which you are plagued with doubt? For example, do you doubt that there is life after death. Even if you soundly believe that there is, can you be sure? After all, if there were, of the billions of people who have died, wouldn’t at least one of them have turned up somewhere? Since, as far as we know, that has never happened, can you be sure of your belief? Are there other things about which you experience doubt? Is doubt inevitable?
Rene Descartes was the world record holder of doubt. He doubted everything to the point that he concluded he could know nothing. He even doubted his own existence! He finally, and famously resolved his doubt by reasoning, “I think. Therefore, I am”. He finally concluded he could know that he existed. Fortunately, few of us experience doubt that we exist. Still doubt is unavoidable. Why is this?
As humans, we can know nothing absolutely. For example, we know that gravity keeps us grounded. But, since we don’t even know how it works, can we be absolutely sure that it will always do so? Doubt is inevitable. To not doubt is to live in a fantasy world. Doubt is a part of the human condition. It is evidence of an engaged mind. It is irresponsible not to doubt. Can we really know anything?
Fortunately, yes! Reasoning conquers unreasonable doubt. It is unreasonable to remain in doubt when reasoning can remove it. We cannot know anything absolutely, but we can know everything we need to know beyond reasonable doubt. We can know it as well as we know anything. We can know it by applying reasoning to our doubt. Are you capable of such reasoning? Of course!
In secondary school, you probably were taught the scientific method. You may recall the scientific method applies careful observation and the application of rigorous skepticism about what is observed. The knowledge it develops is dependent on continual research, looking for findings that refute it. Until the knowledge it establishes is refuted, it remains as rigorously sound as any knowledge we possess.
As well you were probably taught deductive and inductive reasoning. You may recall an example of deductive reasoning such as this. All people have two legs. She is a person. She has two legs. Until either of the first two statements (premises) are shown to be false we can know the third statement (conclusion) is true. In comparison, inductive reasoning applies consistency of observation. Here is an example. Every person we observe has two legs. All people have two legs. Until we find an exception to the premise (such as discovering a person with three legs!), we can know that all persons have two legs. We can know it as well as we know anything. By the way, did you notice that the validity of the first premise in the deductive argument is dependent on the reasoning in the inductive argument?
Is it clear that all human knowledge is subject to continual challenge and vulnerable to correction whenever a scientific experiment or reasoning refutes it? Still this knowledge is as good as it gets. We can know nothing absolutely, but we must know what we can reasonably establish. To fail to establish this knowledge leaves us in unreasonable doubt. It is responsible to doubt, but is it not irresponsible to remain in unreasonable doubt by failing to do one’s best to pursue that doubt with sound reasoning?