We often hear someone say “That’s just a theory” or on the contrary - “In theory and in practice, it always works.” This term may indeed hold in itself a somewhat ambiguous undertone, and lead to confusion and misuse. Let’s look at the origin of the word; according to an etymology dictionary, theory derives from the Greek “theoréo” which means ‘to look at’, ‘to observe’. The definition tells us that one must firstly observe a phenomenon so that a theory about a certain aspect of it could form. There are essentially three forms of theories, and although they are different, all of them have one thing in common – a theory is always born with observation. The first form is theory as a belief, found in humanities such as philosophy and arts – this type is a theory that can guide or predict certain behavior in a social situation. For example: Maslow’s Hierarchy of Needs or the Karl Marx Theory of Bureaucracy. This is when someone might say “That’s just a theory”. The second form of theory is used primarily as a possibility, in other words as a tentative insight into the natural world – for example, the most famous in this category would be the Evolution Theory or in physics a String Theory. Finally, the third form is the scientific theory, and according to www.wordnet.princeton.edu, it is “A well-substantiated explanation of some aspect of the natural world; an organized system of accepted knowledge that applies in a variety of circumstances to explain a specific set of phenomena.” In order for a theory to be considered scientific, it needs to satisfy certain parameters, which distinguishes it from the other two forms. Firstly, a scientific theory will explain how nature works for example Newton’s Theory of Universal Gravitation, or Kinetic Theory of Gases, and it will do so with significant evidence – unlike in the other forms, a scientific theory is always well tested by numerous experiments. This leads to the next point - scientific theories are mathematical in nature, meaning they explain measurable phenomena, and not abstract concepts, such as the theories in the first category. Why did I state that String Theory and Evolution Theory are not scientific theories as opposed to Kinetic Theory of Gases? The answer lies in the hypothesis of these theories. A hypothesis is a proposal intended to explain certain observations, a prediction. It must be testable, meaning that whichever prediction you make, you need to be able to prove it works. It also must be falsifiable, meaning capable of being proven wrong. In both the String Theory and the Evolution Theory, the hypothesis fails, because you cannot possibly test them and also prove them wrong. These are the steps in the formation of a scientific theory: 1. Observation
2. Hypothesis based on observation
First form doesn’t make it to step 3 and second form doesn’t make it to step 4 – only scientific theories make it to step 5. The method outlined in these steps is called an inductive approach to science. It was introduced by Francis Bacon and he said that a scientist needs to erase what he knows in terms of science, and start with a clean slate, tabula rasa; his knowledge will be based on observation, lead to hypothesis, then to evidence (or lack thereof), then to theory and its generalization. The relationship between a theory and evidence is crucial – without evidence, there is no theory and no science, just random observations. To better demonstrate inductive method, let’s take Aristotle as an example. He observed dropping down two objects at the same time, and with numerous experiments he saw that objects which are heavier fall faster to the ground than lighter ones. So that was his theory, and it stayed that way until Galileo Galilei opposed it. This is what inductive method is about – you base your theory on observation and make it a scientific fact until something else contradicts it. It is...