Here I would like to answer the question I asked on Rav Shach in my previous two blog entries.  The question was R. Yehuda and R Shimon both hold we go by the reason for the verse and yet come to opposite conclusions. The answer is this. R Shimon hold we go by both the reason and the literal meaning. You see this in the case in Sanhedrin 21a. He says a king may not marry more than 18 and also not even one that might turn his heart. It is R Yehuda that says we go only by the reason when the reason is written.

So back to our sugia/ subject about marrying a gentile woman. The reason R Shimon says not to marry any gentile woman is not because of going by the reason for the verse, but rather because that is the literal meaning of the verse. In that particular verse the seven Canaanite nations are not mentioned even though that is the larger context there. And if he would only go by the reason for the verse he would forbid only teh seven nations. And the reason R Yehuda who is the Tana Kama [sages] forbids only teh seven nations is when the reason for the law is written in the verse he goes only by the reason which applies only to the seven nations since they are specially more attached to idolatry more than any other nations.