If a whole paragraph reflects – as you stated in your email – one of your sources' explanation (i.e.: an expert) and if this paragraph that you wrote fills more than five (5) continuous lines of text, then you would have to include the equivalent of 20-25 white space on each side of the paragraph (in order to have it centered). The paragraph would not have to be italicized but would still require the inclusion of a footnote number at the end of the last sentence (but before the period). Here's an example:
If you need extra information regarding the horizontal alignment of text on a page, I invite you to visit one of Microsoft's Office Online websites at this Internet address: