If we truly can't go directly to the original source, it's our responsibility to research as much as we can from as many secondary sources as we can, and to be open to corrections and new angles or information from others who've done their homework. He's talking about what the word means, what it means within the belief system that coined the word. On to 'semantics'. Words have power. Words are powerful.
Words have meaning.
Words are meaningful. Sloppy, careless usage diminishes the usefulness of words for their intended purpose - communication . Effective communication relies on words having specific, commonly accepted definitions. When we adopt words from other languages, we are beholden to use it as intended - that IS, after all, WHY the word was adopted rather than translated. I'm also thoroughly bewildered by the notion that insistence on correct terminology is an infringement of anyone's right to believe whatever they want to.