(This is the last article in the series)
I considered including assumptions in my “scientific vocabulary” article, but given how often the concept of assumptions in science is misinterpreted, I decided to be a little more thorough with it.
Reality is very, very complicated, and we as humans are rather limited. Not even the smartest or the most gifted of us can know about everything, or be able to have a complete understanding of everything. This is why science is divided into different disciplines: physics, geology, biology, mathematics, chemistry, archaeology, psychology etc. Each of those can of course be subdivided into other disciplines. As different and unrelated as some of these disciplines may seem to each other, they all overlap. The science of biology have benefitted from discoveries made in chemistry, chemistry have benefitted from discoveries made in physics etc.
One must never forget that the overarching purpose of science is to understand everything, and all of these disciplines affect us all the time. As you sit there reading this, there are physical forces working on your body, chemical reactions happening in your gut, biological processes taking place in your cells, psychology going on in your head etc. All these processes happen everywhere, all the time. The separation of the disciplines do not really reflect reality, but it had to be done in order to study reality. This is why in many cases today, you’ll find multi-disciplinary teams working together, and in order for them all to work together and to be able to integrate all their combined knowledge, there had to be a number of base assumptions made. These six assumptions are common to all the disciplines, to all scientists:
1. Nature is orderly, and the laws of nature describe that order.
When we speak of the orderliness of nature, we speak in terms of regularity, pattern, and structure. For example, when we look at a herd of wildebeest migrating, we assume that it’s not just random behaviour. We justify this assumption through observation by noting the patterns of behaviour, the structure of the herd etc, and thereby come to conclusions explaining their behaviour. The same applies to other natural phenomena. Before Newton’s law was formulated, the motions of the planets were unexplained. We knew they were moving in specific patterns, but we didn’t know why. Newton unravelled the mystery by making an assumption: he assumed that gravity would hold true not just here, but elsewhere too. A universal law that applied everywhere. Of course, we haven’t seen every single star in the universe, or every planet, but Newton’s law have held true at every single star we have observed, and in every single test we have devised, so we can safely assume that Newton’s law is universal.
2. We can know nature.
We assume that we can learn about nature and natural law through observing it. This might seem self-evident, but it isn’t. Until you make the logical assumption that you can learn about something by observing it, you can’t begin to reason about it. Once again, we’re assuming that something is universally true. If I can learn about wildebeest by observing them, can I also learn about, say, the past by looking at the ruins of an ancient city? We assume that we can, and so we do it, and thus far, it’s yielded very good results.
3. All phenomena have natural causes.
We assume that nothing we see is unnatural. If it occurs within nature, then it is a natural occurrence, and if it’s a natural occurrence, we assume that that it obeys some natural law, and that by observing it, we can learn about it. Thus far, this too have held true, and so it was a pretty decent assumption.
4. Nothing is self evident.
“Thunder causes sour milk. Any idiot knows that.” If I told you that, how would you know whether I was telling the truth or not? Would you just accept my word for it? Or would you challenge me about it? Or would you place a glass of milk on your table during a thunderstorm and test my statement? The advancement of knowledge requires that we assume something we know could be wrong, and if that is the case, we should test it to see if it’s true.
5. Knowledge is derived from acquisition of experience.
Learning through observation. We observe the herd of wildebeest migrating every year, and so we predict that, based on their past behaviour, they will continue t migrate. If comes back to observation giving you knowledge.
6. Knowledge is superior to ignorance.
This is a motivational assumption. Knowing more is better than knowing less. This is why we have schools and universities and the like.
These are the basic assumptions science is based on. They’re pretty common sensible, and they’ve held true over the years, so we assume that they’re a solid base to build on. After all, if those assumptions were untrue, then science itself could not have been successful in generating knowledge.
Of course, these are only the broad assumptions that science are based on. There are other, far more specific assumptions that come into play in specific situations.
Scientific assumptions pre-supposes that if something is true, something else will happen in a predictable fashion. Science is a reflection of reality, a model thereof. It is a representation of one small bit of reality to help up understand the whole. Because we’re not looking at the whole in totality, we have to make certain assumptions when we make observations or conduct experiments. We assume, for example, that using a red marker instead of a green marker to label a test tube doesn’t affect the chemical reaction taking place inside. We can test this assumption, and then we assume that it will continue to hold true. We assume that because agar was a good growth medium for bacteria today, it will be a good growth medium tomorrow. We assume that the laws governing bacterial growth will not have changed between now and tomorrow. The assumptions that we make can all be tested, and have been tested. We simply assume that they continue to hold true. If they didn’t hold true, then science would come to a grinding halt. Don’t think that just because a scientists says “Assuming that...”, the assumption he made was pulled out of thin air. It wasn’t.