Philosopher with rule about large historical division (6,4)

I believe the answer is:

berlin wall

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'historical division' is the definition.
I know nothing about this answer so I can't tell whether this works.

'philosopher with rule about large' is the wordplay.
'philosopher with' becomes 'berlin' (I am not sure about this - if you are sure you should believe this answer much more).
'rule' becomes 'law' (law is a kind of rule).
'about' says the letters should be written in reverse.
'large' becomes 'L' (eg in clothes sizes).
'law' back-to-front is 'wal'.
'berlin'+'wal'+'l'='BERLIN WALL'

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I've seen this clue in The Times.

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