judge or a judge？
Apart from those cited one can find, for example, the maxim ,summum jus summa injuria or, again, the affirmation that he must not be judge who does not know what the law contains or what is the reason and the meaning of the law. The interpretation of enacted law in Nordic countries is ruled by the same principles, save for several nuances, applicable in other countries of continental Europe.
Note：Summum jus summa injuria is a maxim which means“ Extreme right is extreme injury.”
此处，提到be judge，而不是be a judge。judge在此表示职务，故表零念，用零冠词。
Nemo debet esse judex in propria causa.
No one should be judge in his own cause.
任何人都不能充当自已案件的法官。
Note:A person ought not to be judge in his own cause, because he cannot act both as judge and party. 其他版本也有用be a judge，将cause用作cause的。
The president recommended him to be judge without qualification.
总统毫无保留地推荐他担任法官。
此类表职务的单词，是单形类名词，例子众多，如：
He was elected president.
I was surgeon successively in two ships.