Concepts of Explanation

The conceptions of explanation are not theories of explanation, and a given concept may be consistent with many theories, and vice versa. Indeed, a good theory will capture aspects of all the conceptions, thus explaining why they all have some intuitive pull.

Reason

An explanation gives us a reason to believe in the truth of the explanandum. This was Hempel's official position.

Sometimes, however, the only reason we have to believe the explanation is that we know the explanandum is true (e.g. the recession explanation for the red shift of galactic spectra).

Familiarity

An explanation makes the unfamiliar and surprising explanandum familiar to us.

However, we often explain familiar things, such as the blue of the sky, in unfamiliar terms, such as the differential scattering of different wavelengths of light from microscopic particles.

Unification

An explanation unifies our knowledge of the explanandum with our knowledge of other things. This is tightly linked to unification models of explanation.

It is difficult to say what, exactly, unification involves.

Necessity

An explanation enables us to see why the explanandum had to be the case.

There are problems with the possibility of probabilistic explanation.

Causal

We explain something by giving its causes. This is closely linked to the causal model of explanation.

Some explanations do not seem to be causal, e.g. explanations in mathematics.

Understanding

An explanation is anything that improves our understanding. See Matthews 1981.

I think that the best available account of understanding is in Chart 2000, but I might be biased.