Simply put: science is awesome. By using our brains and having a passion for experimenting and observing, we are able to deduce the laws of the universe. I am constantly amazed at the very fact that the universe is knowable, in that it is actually possible to figure it out.
But why do I think science is awesome? Many people believe that science is just one way of knowing the universe and that there are other equally valid ways of doing so, or that science only reveals one type knowledge while other types require other means (i.e. religion/spirituality). I, however, would have to completely disagree with that assessment.
I disagree because of the way science is put together. Science isn’t just this giant tome of facts that you have to memorize, it’s a way of finding out how the world works, a method for rigorously and objectively (meaning, without appeals to faith or emotion) discovering how the universe is put together. Now, there is this giant tome of facts that are important to memorize, but that’s just because we’ve been doing science for several hundred years and have accumulated a vast store of knowledge.
But what is it that scientists do? By which I mean, when scientists go to work, what is the method they use? Many of you may have heard of the scientific method, but how does that work? First let’s explore something in logic called modus tolens.
Modus tolens is a logical argument. It follows the following basic form:
1. If A is true, then B is true.
2. B is not true.
3. Therefore, A is not true.
It is also called denying the consequence. In a logical argument, you have premises and conclusions. The premises support the conclusion. In this example, (1) and (2) are the premises and (3) is the conclusion. What is important to understand about modus tolens is that it is deductively valid, meaning that, provided the premises are true, the conclusion cannot possibly be false. It is not logically possible in this argument for B to be false while A is true. Now, of course, one or more of the premises may, in fact, turn out to be false, but that’s a different issue.
The other logical form we must consider is called confirming the consequence. It is similar to modus tolens, except that B turns out to be true like so:
1. If A is true, then B is true.
2. B is true.
3. Therefore A is true.
What is very important is note is that this argument is deducively invalid. The conclusion can be false while the premises can be true. This is because B might actually be true independently of A. Even though this isn’t deductively valid, it is useful in another type of logic called inductive arguments.
Inductive arguments are basically the in-between arguments, that are neither 100% true nor 100% false like deductive arguments. It’s basically an argument of probability: given a certain set of premises, how likely is it that the conclusion is true? It might seem very very likely, approaching 100%, but never reaching it, or it might seem incredibly unlikely, but never reaching 0%.
So what does all this have to do with science? Well, all science basically boils down to these two logical forms and assigns different names to them. In science, you work with hypotheses. Hypotheses are an attempt to explain how the world works. They are like the “A” in the argument. Good hypotheses make testable prediction, meaning you can go out and check whether they are true. This is, in essence, the first premise, which is identical in both forms:
1. If the hypothesis is true, we should observe effects C, D, E, F, G, etc.
A lot of work is put into finding testable predictions and in making sure that the predictions do, in fact, follow logically from the hypothesis. It might take days, weeks, maybe even years of work just to find testable predictions. Sometimes no testable predictions are found and the hypothesis has to be junked, no matter how compelling it may seem.
The second part is the experimenting. It’s basically going out and seeing if C, D, E, F, G etc. actually happen. Again, it’s a lot of work, making sure the experiment is set up right, making sure the data collected are accurate. Experiments are run over and over by many independent groups of people, all trying to confirm or deny the hypothesis’ predictions.
When it’s all done, there are obviously only two outcomes: either the prediction is confirmed (in which case B is true), or it is denied (in which case B is false). If it is confirmed, then we can say that the hypothesis has support, but it is not proven. If is it denied, then we can say that the hypothesis–in it’s current form–is wrong, 100%. At that point, it is up to scientists to see if the hypothesis can be modified to fit the data, or whether it just has to be thrown out altogether, and the process starts once more. It doesn’t matter how much we like the hypothesis, who proposed it, or anything else. All it comes down to are the follow two questions “do the predictions logically follow the hypothesis?” and “are the predictions actually true?”. Nothing else matters.
So when can we say that a hypothesis is proved? Ultimately never, but many hypotheses are tested over and over and are continually confirmed without their predictions being denied, so we are confident that our hypotheses are very likely true. At that point the hypotheses might start being called theories (short for “theoretical model”. For non-scientists, you can think of “theory” as being nearly synonymous with “fact”). Not that there’s an official vote or anything on “promoting” hypotheses to theories, it’s more an informal catagory for hypotheses that are really well-tested and have stood up to scrutiny.
That is why I love science. With such rigorous methods, it’s hard to understand why a lot of people don’t accept it. It may be that such people just don’t understand how it works and think it’s just another belief system on par with all the others that exist. But science isn’t built on faith. It explicity states not to believe on faith but on evidence. Simply put, without evidence, how do you know anything is true at all?