Logical reasoning happens in a completely different part of the brain than language, proving that you do not need words to think.

Patients with severe aphasia who have lost the ability to speak or understand words can still solve complex logic puzzles. Formal logical reasoning does not engage the brain's language network at all. Many philosophers and scientists long assumed that human thought was built entirely out of linguistic structures. These results show that the language of thought is a distinct system that operates independently of the vocabulary we use to communicate. This means that a person's intelligence and ability to reason remain intact even if their capacity for speech is destroyed by a stroke. It fundamentally separates our ability to calculate the world from our ability to describe it.