Paraphrase of last line:

'(Humanity) will never be free until the last king is strangled by the entrails of the last priest.'

---

(Translation from French)

I display the times; I appeal to the age

The public is never advantaged

Certainly, mankind has not sacrificed its rights;

If mankind dared but to listen to the voice of its heart, changing suddenly the language,

It would say to us, as it would to the animals of the woods:

Nature created neither servant nor master;

I seek neither to rule nor to serve.

And its hands would weave the entrails of the priest,

For the lack of a cord with which to strangle kings.

-Denis Diderot