I'm surprised no one has challenged that statement. Logic is making deductive statements that are true. One only needs symbols for this. That's why computers can prove mathematical theorems. Words are necessary because we are human and we need to communicate are base assumptions which normally come from the natural world. Saying logic necessarily uses words is like saying logic necessarily uses eyes or ears.
Actually this is only half true. Formal logic relies on words because some concepts, like finiteness, are impossible to grasp within the formalism itself. A good textbook on this is “Gödel's Theorems and Zermelo's Axioms A Firm Foundation of Mathematics”, which spends the early chapters dedicated to making you aware of this issue.
I'm surprised no one has challenged that statement. Logic is making deductive statements that are true. One only needs symbols for this. That's why computers can prove mathematical theorems. Words are necessary because we are human and we need to communicate are base assumptions which normally come from the natural world. Saying logic necessarily uses words is like saying logic necessarily uses eyes or ears.