Re: leave here
"UK system has common law, precedent,"
Correct, basically common law is made by tradition and not codified, therefore more difficult to know. Though in practice most of our life is governed by statute law (made by parliament) and case law (made by the courts) For most of us the contracts we enter into also have a major impact on our lives (and in practice they're little different between the common law and Roman law traditions).
"and is also based on 'that which is not banned is allowed'."
"EU ( most ) no common law, no precedent"
IANAL but: Roman/civil law traditions are, in practice, not that different from common law traditions. Court decisions form precedent, just like in the UK.
" and based on 'that which is not allowed is banned'."
Not that again! Please quote a source. I'm not a lawyer but I have read a fair number of textbooks on English and Dutch law and I've never come across that. This unfounded claim has been bugging me for years. It's propaganda at its worst, repeated without foundation. Basically a sodding lie.
And while slating Roman/civil law please remember that Scotland has does not have a common law system either, more of a hybrid. Oh, and for the last X centuries folk practicing common law have been exceedingly fond of using Latin terms so it must have held some attractions to them.