Inscription for Thoth tattoo

I would like some insight on how to render "Magic is only method that is not yet understood" into Latin. I have gotten "veneficus est tantum ratio ut est nondum agnosco" from a bot, but I don't like it because 1) "veneficus" has a negative connotation; I want to use "magia" instead; 2) I prefer "modo" for method; 3) I like "conceptum" better than "agnosco". The best I can do so far is: "MAGIA MODUM MODO NONDUM CONCEPTUM EST." I'm not sure if I got my cases right. Does the direct object take the accusative case? Or does it agree with the subject and take nominative? Or am I completely off base and this is an appellation?? I forget. Also, "modum modo" seems a little redundant, but those are the two words that I find fit the nuances of the orginal English best; I'm not sure there are suitable alternatives.

Any ideas? (This is for my next tat so it has to be rock solid. I don't want to bother my prof with this because I don't want him to think I'm a fruitcake!)