The publication, Defending a Higher Law: Why We Must Resist Same-sex “Marriage” and the Homosexual Movement, from Tradition, Family, and Property, printed in 2004, is now available online in PDF form here. It is normally available for purchase from TFP for $12.95 - but now you can get it free as a download. It is a very important book which not only presents Church teaching on the subject of homosexuality - through the ages, but it also traces the genesis and history of the homosexual movement in modern times, which has set the stage and prepared the place where we find ourselves today. I can't recommend it more highly, except to say, amongst those who do recommend the book, and endorsed it in writing are Archbishop Nienstedt and Bishop Fabian Bruskewitz.
Since the online document is in PDF form, it is difficult to excerpt and format. The following is an example.
SAME-SEX ‘MARRIAGE’ IS OPPOSED TODAY AS
INTERRACIAL MARRIAGE WAS OPPOSED FIFTY
YEARS AGO. IT’S PURE PREJUDICE!
This contention is false. First of all, one cannot compare two
essentially different realities. A man and a woman of different
races are not comparable to two men or two women.
A man and a woman wanting to marry may be completely
different in their characteristics: one may be black, the other
white; one rich, the other poor; one learned, the other not; one
tall, the other short; or one may be famous, the other unknown.
None of these differences are insurmountable obstacles to
marriage. The two individuals are still man and woman, and
thus the requirements of nature are respected.
Same-sex “marriage” opposes nature. Two individuals of
the same sex, regardless of their race, wealth, stature, erudition
or fame, will never be able to marry because of an insurmountable
There is simply no analogy between the interracial marriage
of a man and a woman and the “marriage” between two
individuals of the same sex.
Secondly, inherited and unchangeable racial traits cannot be
compared with non-genetic and changeable behavior. - Defending a Higher Law
h/t Ray at Stella