suggesting that the tekhelet is invalid. According to halakha, when in doubt about the laws of a commandment from the Torah, one must act stringently. Some rabbis therefore argue that even if we are uncertain in our identification of the hilazon, we must wear the most likely dye anyway (i.e. Hexaplex). Others disagree, asserting that the principle of stringency only applies in cases such that after one acts stringently there is no further obligation (whereas if Hexaplex is only doubtfully correct, there would remain a theoretical obligation to find the actual correct species and use it). Based on , the Talmud rules that we should not make divisions among the Jewish people. Therefore, if a person acts differently from the rest of the Jewish people they are creating divisions. Some have argued that one should not publicly wear tekhelet for this reason; others consider this not to be a concern. In any case it would not be relevant in many contemporary communities where tekhelet-wearing is widespread. There exists a Torah commandment (לא תגרע) not to detract from any other Torah law. Rabbi Hershel Schachter says that if one knows what tekhelet is yet chooses to wear tzizit without tekhelet, they are violating this commandment. Many other rabbis do not agree with this statement. Tying methods Maimonides holds that half of one string should be colored blue and it should wrap around the other seven white strings. It should wrap around three times and then leave some space and then three more and leave some more space and should continue like this for either 7 or 13 groups. The first and last wrap around should be from a white string not a blue string. Raavad holds that one full string should be blue and there should be four groups of at least seven coils alternating between white and blue both beginning and ending with blue. There are multiple other opinions of how to tie the tzizit if one full string is blue. Tosafot holds that two full strings should be tekhelet. He is of the opinion that the coils should be in groups of three, starting with three white, then three blue alternating and ending with three white. There is another way to tie using two full strings that Schachter follows based on the opinion of Shmuel Ben Hofni Gaon. Tekhelet in Jewish culture Besides the ritual uses of tekhelet, the