Is deep down an paradox or oxymoron?

"Deep down" is considered an oxymoron rather than a paradox. An oxymoron combines contradictory terms, as "deep" implies a sense of profoundness while "down" suggests a lower position. In contrast, a paradox presents a seemingly contradictory statement that may reveal a deeper truth. Therefore, "deep down" captures the complexity of emotions or thoughts that may seem conflicting yet coexist within a person.