In 1984, what does Newspeak refer to according to Winston's friend Syme? What is its ultimate purpose?

In Part One,
Chapter Five
of ,is lectured by his friend Syme on Newspeak, which is
the
official language of Oceania. Syme is an expert on Newspeak because he
works in the Research
department of the Ministry of Truth and is involved in
the writing of the eleventh edition of
the Newspeak dictionary. 

According to Syme, the essence of Newspeak involves
"cutting
language down to the bone." In other words, it involves the elimination of

words which the party deems unnecessary. We see this in Syme's handling of
adjectives:

"A word contains its
opposite in itself. Take 'good,' for
instance. If you have a word like
'good,' what need is there for a word like 'bad'? 'Ungood'
will do just as
well."

He goes on to say that the

purpose of cutting the language down is to "narrow the range of thought" and
therefore
eliminate the possibility of ever committing Thoughtcrime. It
simply won't be possible to think
something bad about the party because
Newspeak will have removed all the words that make these
feelings
possible.

On a deeper level, the development of Newspeak is
about
enabling the party to control people's thoughts. They already control
people's movements through
the telescreens, but Newspeak will allow them to
enter people's conscious and unconscious
thoughts and manipulate them
accordingly. If people are unable to articulate their
dissatisfaction with
the party, for example, they will (theoretically) be unable to feel it. And

this, in Syme's words, will signal the party's total control over Oceania: "The
Revolution
will be complete when the language is perfect. Newspeak is Ingsoc
and Ingsoc is
Newspeak."