Grammatically speaking we say The Tarot/The anything because there is one.
We say The Sun, The White House, The World as it specifies either one (in the world) or it is generally understood that we know which one is being referred to (i.e The Door is probably the front door, The Queen is probably Queen Elizabeth). The Tarot is generally undertood by everyone to be referring to one particular tarot. Like The Bible.
However, if you wanted to be more generic, you would omit the article, i.e Tarot is bad for your health, like Alchohol/Smoking is bad for your health. We say Poverty is depressing, Nature is beautiful because we are referring to the things in general, as a general idea...(distinct from The Poverty in Latin America, the Nature on the Galapagos Islands, i.e more specific)
Am I making sense? OK, grammar lesson over