This week, principle met Coalition government head on and war broke out.
The cause: the Lords’ Reform Bill.
Ninety-one Tory MPs voted against this misconceived jumble of measures.
I was among them.
Make no mistake, I believe reform is necessary, but we need to tread carefully.
Amongst all that pomp and ermine is an abundance of wise heads: scientists, military officers, professors, authors, historians, businessmen and bishops, to name but some.
Such experience and expertise has meant proper scrutiny of government legislation for centuries.
The Bill proposes that we retain 90 of these wise heads and elect the rest.
It all sounds reassuringly democratic until you realise that the other 80 per cent would be chosen from Party political lists and elected under a different system to MPs.
The independence of mind and breadth of life-experience, which has characterised the Upper House, would be lost.
They’d be replaced by so-called ‘senators’, elected by us all, with the certainty they’d undermine the legitimacy and primacy of both the MP and the Commons.
The current role of the Upper House is to revise and advise.
An elected chamber would encourage a more combative approach, leading to legislative deadlock and controversy.
While outside Westminster, the likelihood of the elected, regional ‘senator’ locking horns with a constituency MP from another Party is inevitable.
And, why not? These ‘senators’ would be elected for one term of 15 years, with no one to answer to.
Sensible reform is obvious: fewer Lords overall – there are currently 823, of whom about a third were appointed by Tony Blair – reduced political patronage, no criminals, a system of retirement and a review on who is appointed and how.
But keeping the Coalition sweet is not a reason to vandalise this ancient constitution.
The Lords has curbed the excesses of both left and right for centuries and I will not see a grubby compromise stain our democracy.