I've read a lot of the comments and a lot of guess work being applied as, "True fact!"

There are two sexes. Intersex is NOT a unique sex. Intersex is a term that can cover a variety of genetic and biological abnormalities that lead to some sexual ambiguity. These resulting abnormalities do not classify a human as a third sex, but a resulting condition of abnormal development.

For instance in Congenital Adrenal Hyperplasia a person is born with female genitalia both inside and outside the body. There is no male sexual organs present. This is a condition that is caused by adrenal glands over producing in utero. This may lead to inhibited development later during puberty resulting in male physical characteristics and sterility. This is the most commonly seen form of intersex persons.

Now, this is in no way a third sex. The person in this example is quite clearly an XX-female with genetic abnormalities that inhibit proper function.

There are other conditions such as Kleinfelter's, Anorchia, Turner, Triple-X, etc. These are clear aberrant conditions created by problems in the biology of the person. In many, if not most, cases we can tell exactly what the "base sex" of the person is, and detect where it went wrong (this isn't 1950!). However, in those cases where the sex is truly ambiguous, it is silly to say it is a resulting third sex. Rather, it is that our medical science is lacking. There is clearly a reason why the condition happened, and to say, "Oh contrary to all established patterns we've ever observed, this is clearly a third sex." Is silly. That's like when physicians dealt with the four humors because they were ignorant of cellular biology.

Acknowledging the biological reality of the situation isn't hateful, nor does it condone hateful treatment of those exhibiting the condition. It just is. Sometimes tragic and difficult things happen, and it sucks. It sucks if you're different, or abnormal, and it sucks if people treat you shitty for it, but bending biological terminology, and ignoring reality, doesn't help either. It inhibits understanding and produces further stigma.