Models vs. Theories

In the Forbes article “What separates a good scientific theory from a bad one” there is the following quote that got me thinking:

While Ptolemy and Copernicus are perhaps famous for putting forth the two major concepts for models, geocentric and heliocentric, these are only models, not theories. Why’s that? Because for every planet you introduce, there’s no rule or law governing how it orbits. These models simply state that if you supply the correct parameters, like equants, deferents, and epicycles for Ptolemy, you can describe a planet’s motion through the skies.

A descriptive model is an important step, but it isn’t a full-fledged scientific theory. Principles are a great starting point, but they won’t get you all the way to the end. For that, you have to go a step further: you need a rule, a law, and/or a quantitative set of equations that give you the ability to make predictions about things you have not yet measured. Kepler’s laws were the first leap in that direction. They didn’t simply accurately prescribe the orbits’ shapes and paths (ellipses, with the Sun at one focus), but begin to quantitatively describe it. Kepler’s second law gives the relationship between the orbital speed and the relative distance from the Sun, while the third law gives the relationship between the orbital period and the semimajor axis. For the first time, it wasn’t just that a behavior could be described through a set of parameters, but predicted. [emphasis mine]

That just makes me wonder how far we are in linguistics compared to physics. We’re beyond Ptolemy, but are we really even at a ‘Kepler stage’? Are the theories we have right now really theories in the Newton sense, or are they models that consist of a limited toolbox whose tools are applied to make the data fit (equants, deferents and epicycles for Ptolemy, functional heads, movement and silent elements for linguistics)?

A caption under a depiction of the geocentric and heliocentric models reads: “As interesting as both of these models are, neither one would have very much to say if another, new planet were discovered.” Hopefully we are beyond that point. At least we’re in the heliocentric version of linguistics since it is placed in the context of cognitive sciences (and ultimately biology, as some love to say).

But maybe we really are at a pre-galilean stage in linguistics, as it is sometimes mentioned.

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