But it need not be thus
This sentence boggles me. I expected to see "it needs not" or "it does not need to". What am I missing?
But it need not be thus
This sentence boggles me. I expected to see "it needs not" or "it does not need to". What am I missing?
This is "modal need". The English verb "need" can be used as a normal verb
He needs a drink. I don't need a break.
And as a normal verb it has normal grammar. It is transitive and takes a direct object.
But need can also function as a modal verb, like "can" or "will". And modal verbs are defective. Remember you say "He will not be..." and not *"He doesn't will be".
When "need" functions as a modal verb, it is the auxiliary and it doesn't take "s" in the third person.
He need not be ...
Use of "need" as a modal verb is becoming less common in English, so this construction is formal and rather old-fashioned, it is almost never used in positive sentences. It is being replaced by a catenive construction with a normal verb and a "to" infinitive
It need not be thus. → It does not need to be like that.