One of the questions which gets much emphasis nowadays is whether the Torah discriminates against kohanim who have some kind of deformity, blemish, or disability. This is an outcome of looking at the Torah through the lens of 21st century morals; anything in the Torah that doesn’t strike us as being up with the times is fair game for attack.
Honestly, that’s the game many people play today, using emotional (and almost never intellectual) arguments to explain why certain laws and policies are discriminatory. Let us be clear — there is never a good counter argument against an emotional argument. However, when emotions are removed from an argument, and facts, figures, and information can be debated, then we can have a fair winner, and a decision/policy/law that can be agreed upon by consensus.
So if we are looking at the Torah purely from an emotional vantage point, the answer would likely be, “Yes. The Torah is discriminating.” But to accept the premise of this argument, we need to understand the difference between discrimination and protection.
While I am certainly able to try out to be in the NFL, the fact that my age, inadequate frame, disproportionate body fat, and lack of muscle tone would prevent anyone from offering me a contract. This less discrimination as it is for my protection. Do I cry and scream “Discrimination in the NFL?” Or do I say, “I’m better suited for a different line of work.”
There is a physical prowess needed for kohen work. And there is also a need for a certain kind of perfection in service, the lack of which could be deadly (think of Nadav and Avihu). Would it be proper to put people who, through no fault of their own are incapable of serving properly, into positions where they have to perform at a certain level, and where, if they fail they may die?
That is protection — but is it also discrimination? On an emotional level, perhaps, but not on an intellectual level. Additionally, these kohanim are not denied any of the benefits of the priesthood; they can eat all of the special foods kohanim eat, they can receive the special gifts the kohanim are gifted, and the rules of purity/impurity still apply to them, they can be given the kohen aliyah, can bless the people, and can serve for the Pidyon HaBen ritual. What is denied to them is permission to serve in the ritual service of the Temple.
According to Or HaChaim, when Moshe told G-d at the burning bush to send someone else (Shmot 4:13), he was saying, “In the hands of someone who is worthy to carry out Your mission, not in a weak person such as myself, who has a permanent mum (blemish), and this is a demonstration of my being unfit for such a lofty mission.” It takes a sense of self and awareness of how others perceive you to be able to take a step back and say, “This is not the job for me.” Obviously G-d wanted Moshe for many other reasons!
In his commentary on both Vayikra 1:3 and 21:17 (look them both up!), Rabbi Samson Raphael Hirsch elaborates in great detail how the kohen who would serve in the Temple needed to be of the same caliber as the animals which were to be brought as offerings — without blemish. (See Malachi 1:8 who decries bringing animals that have blemishes.) The prophet Hoshea rebuked the priests in the Northern Kingdom of Israel who used their sanctuaries as a haven for the blind, lame and sick to seek consolation for their suffering.
G-d’s altar demands the whole person — and the offerings are to be without blemish. And such, the kohanim who represent the people are to be without blemish. The wholeness of the animal is representative of our giving our whole selves to G-d, as we declare in the second verse of the Shema (Devarim 6:5).
Should we treat people who are afflicted with disabilities or “differences” with respect? Of course! We should never diminish the humanity of anyone, as all people are created in G-d’s image. The question only becomes what is the right role for everyone in society. And in the case of the Temple, the Torah is clear on who can serve, while never denying the rights and benefits of priesthood from those who are declared unable to serve.