This relates to—guess what—knowledge in Siddhartha. While knowledge can be conveyed using words and while such communication is necessary and useful, it is inherently deceptive. The wisest characters in Siddhartha tend to be extremely skeptical of words. (They use ESP instead. Just kidding.) Enlightenment lies in the realm of the incommunicable. It must be experienced.
Questions About Language and Communication
Does verbal communication play a positive role in the spiritual progressions of the characters in Siddhartha?
How does the river speak to people?
What kind of communication is most effective in Siddhartha? Speeches? Body language?
Chew on This
Enlightenment in Siddhartha is communicated physically rather than verbally.