Which of you can differentiate / differentiate between the transitional and intransitional usage of the verb to differentiate?

For instance, can you use the following example sentence with and without preposition. If so, does it make any (tiny nuance of a) difference?

1) The students have learnt to differentiate (between) different parts of speech.

Recently, Iīve stumbled on the following construction:

2) The students can differentiate the long-term and immediate causes of the French revolution.

Apart from the fact that it seems to me that long-range is not used here properly as it implies bridging a period of time ahead, but not back in time, wouldnīt differentiate between be preferable here?