Subject: VRD: first ,second and nth quantisation

I had several occasions to meet in the litterature
 the following expressions:"first ,second and
nth quantisation " so as to make us thinking that exists
many quantum theories which differ from each other by the
level of quantisation. For example in the free electronic
 book of philip Gibbs available on the world wide web
at http://www.weburbia.com/press/esst.htm it's stressed
the following:
"Second Quantisation:
There is a twist in the tale of quantisation which was introduced by
Pascual Jordan in 1925. A single particle which is quantised
becomes a field, i.e. values assigned to each point in space like the
classical electromagnetic fields. A field theory can also be derived
from a principle of least action and can therefore also be quantised.
The field theory of the single particle Schr*dinger equation can be
quantised in this way as if it were a classical field. The result of this
second quantisation works out to be the same as the quantum theory
of a many-particle system. The Schr*dinger equation is linear but
quantisation can be applied to field theories with non-linear terms.  The 
interaction between the electromagnetic field and Dirac's
equation for an electron is a non-linear relativistic generalisation of
the Schr*dinger equation. This is still called second quantisation but
> >not everyone likes the term used in this way. Many physicists prefer
> >to think that the first quantisation was a mistake and quantum field
> >theory alone is correct."  and so in the other chapters.
> >I would be very grateful to you if send me an explanation.
> >Thanking you in advance
> >sincerly

Re: VRD: first ,second and nth quantisation