body of fact

I couldn't find a definition for "body of fact". Anyone could help me pls?

The sentence:

"Doubt is our product, since it is the best means of competing with the 'body of fact' that exists in the mind of the general public."

Brown & Williamson Tobacco Corporation

Leonardo, this is the definition of "body" that applies to your example:

"A collection or quantity, as of material or information."

"Body of fact" in your sentence refers to all the information about tobacco/smoking that is now common knowledge among the general public.

"Doubt is our product": This sounds like a Public Relations exercise, to caste doubt on "the body of fact" ie the generally known opinion that smoking is bad for you - in the mind of the general public.

So, the Public Relations Firm is encouraging people to doubt the received wisdom, that smoking is bad for you.

Thank you Deborah and Robin.

I think the following definition would also apply for "body": a large amount of something:
There is a growing body of evidence to support their claim.
She collected a huge body of information on the subject.