Evolution in Fact and Theory, Revisited
Around the 30th anniversary of the publication of Stephen Jay Gould's essay with a similar name, Larry Moran has reposted his essay "Evolution Is a Fact and a Theory." His article begins by blithely accepting the confused terminological protocol that uses the same word, "evolution," to describe very different things: a) the observation that life forms have changed over vast stretches of time, and b) a set of proposed observations regarding how, by what mechanisms, the forms of life have changed.
You don't have to be a philosopher to sense that using the same word to designate different things, in a contentious context like this, is bound to result in confusion if not abuse. It surprises me that folks in biology don't establish a more precise vocabulary, unless the confusion serves a purpose they'd rather not admit even to themselves.
In any event, regarding the assertion contained in Moran's title, Casey's formulation has a lot to recommend it:
When evolution is defined as mere change over time within species, no one disputes that such evolution is a fact. But neo-Darwinian evolution -- the great claim that unguided natural selection acting upon random mutations is the driving force that produced the complexity of life -- has many scientific problems because such random and unguided processes do not build new complex biological features. Neo-Darwinian evolution is a theory that has been falsified by the evidence.