* agree on the meaning of the words you use. Agreed, this is very important. One way to handle it when the two of you have different meanings for a word is to

* agree on the meaning of the words you use. Agreed, this is very important. One way to handle it when the two of you have different meanings for a word is to keep using the word, but add a different qualifier in front for each meaning, i.e. logical proof versus empirical proof.