Reply To: Arba Kanfos without Techeles

I know I’m wrong but I can’t figure out why.

Tzitzis is not a chiyuv unless someone already has Arba Kanfos so not wearing them when one is not mechuyev isn’t a bittul mitzvah (simularly I was never mevatel the mitzvah of eglah arufah).

The reason why we wear arba kanfos is because we want to fulfill even the mitzvos that we are not mechuyev.

Most rishonim hold (and I beleive that the psak is) that if someone does not have kosher tzitzis, they are not allowed to wear arba kanfos.

Why is the law different when someone doesn’t have kosher techeles?

Are any on my premises wrong?

Is my reasoning that a person may not create a chiyuv mitzvah on himself that he can’t fulfill flawed?

Is a person allowed to create a situation that is mechayiv two mitzvos if he can only fulfill one of them? (If you answer yes make sure you have backing.)