"An essay on criticism"

[wildsky]

In these following lines:

Those RULES of old discover'd, not devis'd,
Are Nature still, but Nature Methodiz'd;
Nature, like Liberty, is but restrain'd
By the same Laws which first herself ordain'd

What is the figure of speech? I don't think it is personification, but is it a simile or an analogy?

Also, what is the paradox here?

[Scheherazade]

Have a look at the literary terms dictionary to familiarise yourself with some of the terms you have used:

http://www.babylon.com/define/58/literary-terms-dictionary.html