Legal Definitions - ipse dixit

Ipse dixit is a Latin phrase that means "he said it himself." It refers to a person's own assertion without relying on any authority or proof. This usually implies an assertion of authority, as in a statement is true based on the speaker's authority and nothing else. In legal context, the term is used to criticize arguments based solely upon authority and not backed by any proof.

"An expert's simple ipse dixit is insufficient to establish a matter; rather, the expert must explain the basis of his statement to link his conclusions to the facts." - Earle v. Ratliff, 998 S.W.2d 882, 890 (Tex. 1999)

This example illustrates how ipse dixit is used in a legal context. It shows that an expert's statement alone is not enough to prove something. The expert must provide evidence to support their statement.