My Lincoln example

we need to distinguish logical implication from empirical investigation.

Suppose the answer to:

“What did Lincoln believe about slavery?”

is:

Lincoln believed slavery should ultimately be abolished.

That does not automatically answer:

“How did Lincoln's language about slavery change over time?”

because his belief may have remained constant while his language changed.

Nor does it automatically answer:

“How did his statements relate to wartime political strategy?”

because knowing his belief does not automatically establish how he translated that belief into strategy.

So the first question may provide evidence relevant to the other two, but it does not necessarily answer them completely.

For example:

Belief is what he thought.

Change over time is whether and how that thought developed.

Political strategy is how those beliefs interacted with political circumstances and decisions.

They overlap, but they are not identical questions.