My grandson, Zachy Wolf, is in pre-K, and yesterday he asked me to print coloring pictures of a bull and a bullfight.  As he sat next to me, busy with his markers, he said, "This bull is kosher. Look at the split in his hooves. But, Bobbi, why can't I see the other thing that makes him kosher so I can color it too? "  Clearly, he knows his Parshat Hashavua.

Parshat Shemini introduces signs of kosher and non-kosher animals:

:... זֹאת הַחַיָּה אֲשֶׁר תֹּאכְלוּ מִכָּל-הַבְּהֵמָה אֲשֶׁר עַל-הָאָרֶץ (ויקרא: י"א, ב).

        ...this is the creature that you may eat among all the animals on earth (Leviticus: 11,2).

The Sefer Hachinuch explains that there is a מחלוקת, a dispute, between the Rambam and the Ramban regarding this passuk.  The Rambam counts this as one of the positive commandments within the 613 mitzvot. He maintains that, in addition to the prohibitions against eating non-kosher animals,  there are separate obligations to check the signs of animals, birds, grasshoppers and fish in order to distinguish between that which is טהור and that which is טמא. However, the Ramban (in support of the בעל הלכות גדולות) only counts the prohibitions againsteating non-kosher animals in  תריג. He maintains that, once the Torah forbade specific categories of animals, it is a natural prerequisite to check the animals; however, these are not separate mitzvot.   

The Rambam classifies the laws of forbidden foods in Sefer Kedusha, the Book of Separation/Sanctity.   When we abstain from eating categories of food that are forbidden, we are separating our higher "selves" from our animalistic desires; we are moving in the direction of kedusha. As I listened to my Zachy, an understanding of the Rambam's view occurred to me. Perhaps he maintains that the objective of מאכלות אסורות (forbidden foods) is not simply abstention and control over this area of instinctual behavior. The Torah is teaching us that we achieve greater kedusha when that abstention is the result of an intellectual process.  It is important to gain a precise understanding of subtle halachic distinctions and then express them through the act of either eating or abstaining. Therefore, בדיקה, checking the signs of kashrut, is a positive obligation.

The Parsha concludes with:

      להבדיל בין הטמא ובין הטהר וביו החיה הנאכלת ובין החיה אשר לא תאכל (ויקרא: י"א, מ"ז).  

To distinguish between the impure and the pure, and between the animal that may be eaten and the animal that may not be eaten (Leviticus: 11, 47)

To achieve Kedusha, it is not enough to exercise control over the animal instincts. We must actively engage the liberated soul in the intellectual process of distinguishing; we must define clear categories and concepts.  For the Jew, that process begins in pre-K and continues for a lifetime.