As a public speaker, you have an ethical duty to research your topic so that you can be sure the facts you present to your audience are accurate. If your research reveals that a fact is supported by a consensus of credible sources, you can confidently use that fact in your speech. Conversely, if you find that the jury is still out on a claim you wish to make, don’t present that point as an established fact. Instead, acknowledge that the point is being debated. Then use a two-sided argument to show why you believe the support for your side outweighs the support for the other side. If you find that few credible sources support your claim and that most sources disagree, do not include the point in your speech. Research other arguments for your position instead.