We are an eco-furniture company and we'd like to use famous quotes inside our furniture, can we?

It's ok to use quotes, they're public domain in the sense that they're not protected by copyright law, and not likely to be protected by the speaker's right of publicity in their name.

Disclaimer: Please note that this answer does not constitute legal advice, and should not be relied on, since each state has different laws, each situation is fact specific, and it is impossible to evaluate a legal problem without a comprehensive consultation and review of all the facts and documents at issue. This answer does not create an attorney-client relationship.

The following is not legal advice and should not be relied upon to take or refrain from taking any action.

The answer to each of your questions, unfortunately, is "it depends." There are two bodies of law that need to be considered: copyright law and trademark law.

As for copyright law, the starting point when thinking through the issue is the rule that short phrases such as quotes are NOT copyrightable. See 37 C.F.R. § 202.1 at < http://tinyurl.com/clr6bf > and < http://tinyurl.com/dzza5s >. Indeed, when news organizations publish facts written by others, courts have held that entire paragraphs are sometimes not copyrightable.

Courts have applied this rule often (e.g., to the phrases “Listen Up, It’s More Than Talk, It’s Feeling” / “You Got The Right One, Uh-Huh” / “Protecting The Earth From The Scum Of The Universe" / “You’ve got to stand for something or you’ll fall for anything” / “Eat Your Art Out, Chicago” / "Priority Message: Contents Require Immediate Attention"). None of these phrases are copyrightable.

However, courts sometimes apply the rule that when a single line of a larger copyrighted work (such as a movie or poem) is used by someone other than the copyright owner, the test for infringement is whether "the work is recognizable by an ordinary observer as having been taken from the copyrighted source." If so, the court may find that copying that one particular sentence is an infringement of the copyright in the movie or poem. Moreover, if a phrase has become so well known that it may be considered "the heart" of a copyrightable work -- e.g. "ET phone home" -- then the court will find a way to preclude anyone other than the copyright owner to use that phrase. Especially for commercial purposes. So ... as far as copyright goes, you're on safe ground as long as the quote is not "the heart" of a larger work and it's only a minor portion of the work (you need to consider this second condition seriously when using quotes from poems).

As for trademark law concerns, many short phrases are used to brand goods or services. Before you slap a phrase on a product and then offer it for sale, you need to ensure that the phrase you've selected is not already being used as a trademark. You also need to be aware that trademark law proscribes the sale of products that consumers falsely believe are being offered for sale by a particular person or company or are falsely associated with that person or company.

Before you begin to sell any products that exploit the work of others (and, yes, creating quotes is work) you need to discuss the matter with an intellectual property attorney. While short phrases are very often part of our rich public domain, some are NOT and so using them requires permission.

Sure you can but it depends, if the quote is in the public domain, meaning the copyright expired, or in practical terms the author has been dead for more 70 years, then you are free to use them, otherwise you should check before using.