That's a famous quote from Franz Kafka.
if none observe me, I have to observe myself all the closer.
That's a famous quote from Franz Kafka.
if none observe me, I have to observe myself all the closer.
None can be singular or plural, depending on what it is referring to.
Here it is referring to "the people". A fuller reading of the quote might be:
if none of the people observe me, I have to observe myself all the closer.
The people is plural, and so takes the plural verb observe.
It should be pointed out that it's not so much about a hard-and-fast rule but about clarity. If you’re wanting to emphasise “not any amongst many” as in the above example then you should use the plural to make this emphasis clear. There’s a good discussion of notional agreement here http://dictionary.reference.com/help/faq/language/g11.html
ODO's usage section isn't quite as explicit, but does mention it depends on the emphasis needed http://oxforddictionaries.com/definition/english/none
Even though some disagree, none can have a plural meaning. For instance:
(…) while the police found 170,425 images, none were classed as indecent. (The Telegraph.)
So we could interpret none in if none observe me as plural. However there is nothing in the fuller quotation to force on us that reading of none:
This inescapable duty to observe oneself: if someone else is observing me, naturally I have to observe myself too; if none observe me, I have to observe myself all the closer. (Franz Kafka, November 7, 1921.)
Now, in my admittedly limited research, all plural ‘nones’ I have found referred to a plural noun in the preceding clause, as the 170,425 images in the example above, or were part of expressions such as none of them. This is not the case in the Kafka quotation.
So, we should consider another possibilty. If none observe me may be an old-fashioned use of the present subjunctive in conditional sentences (see also here), as in:
If he be found guilty he shall be hung.
With observe, whether none be singular or plural, the same structure is:
If none observe me I have to observe myself all the closer.
The subject is None which can be both singular and plural. It's a misconception that it is always singular.
if none observe me, I have to observe myself all the closer.
Here, none is plural, so it took a plural form of verb Observe.
In the next part of the quote, to observe is infinitive. When you use an infinitive verb, the “to” is a part of the verb, and the verb is always just the verb. It’s not conjugated in anyway – no -ed, no -ing, no -s on the end.
Multiple answers have pointed to "none" as being optionally singular or plural. While we can't really say for sure why the author (or rather, translator from Kafka's German to English) chose this phrasing, I have a different theory.
It is the subjunctive mood.
The subjunctive mood is used (among other things) to express hypothetical scenarios, such as ones following an "if". In English, in the present tense, the subjunctive has the same form as the infinitive (without "to").
If he be willing...
If the dog steal my bacon...
If none observe me...
In modern usage, the subjunctive is very rare, especially the present subjunctive. (The past subjunctive, using "were", is slightly more common.)
Further reading: Wikipedia, "English subjunctive"
Incidentally, I don't agree with those other answers that say "none" can be singular or plural. I would always take "none" to be plural. But that might be dialect-specific, and someone who has a good book on grammar handy can speak more authoritatively than I can.