“Tell Bnei Yisrael, ‘These are the creatures you should eat.’ ” – Vayikra 11:2
Chovos Halevovos (Sha’ar Avodas Elokim 3) explains that Hashem created man out of two very distinct parts – a nefesh haschili (intellectual soul) and a nefesh habahami (animal soul). Each has its desires and inclinations, and each is competing with the other, vying for primacy over man.
The sechel in man is what drives him to do all that is good and proper. It is the part of him that pulls him closer to Hashem. It is the force in him that hungers to help others. Everything that is noble, proper and good in man stems from this side.
The nefesh habahami on the other hand is comprised of the base instincts necessary for survival. This is a part of man just as it is in the rest of the animal kingdom. It is made up of hungers, appetites, and desires.
The sechel and beheima are constantly in competition with each other, and each is in a state of flux. Much like a muscle, each becomes stronger with use and atrophies with disuse. The more a person uses his sechel, the stronger and more dominant it becomes. The more he allows his passions and desires to rule, the stronger a hold they have on him. Man is engaged in a constant battle.
In this conflict, the beheima has an unfair advantage. It is in its element, and everything that we do constantly utilizes it and therefore strengthens it. All of man’s daily activities – from working for a living to eating and sleeping – are constantly nourishing the beheima side. Very little that a person does strengthens his sechel. And so by all rights, the behaima side of man should become ever stronger until it vanquishes the sechel.
For that reason, the Torah gave us strict instructions about which actions to engage in and which to avoid, as those actions give an undue strengthening to the beheima side of man.
Chazal tell us that “treif food deadens the heart.” When a person eats non-kosher food, he ingests that impurity into himself, so his beheima side becomes stronger, and it becomes more difficult for him to relate to anything spiritual. It becomes harder for him to learn, harder for him to daven, harder for him to experience Hashem.
When Chazal call not eating treif food a chok, that refers to how it functions. Why does milk cooked together with meat give an unfair edge to the beheima side? Why does ingesting blood make a person cruel? To understand how these things function, one must be a scientist of the soul – something that very few individuals in history were able to become. But that it works that way is a given. And for that reason, the Torah forbids us from eating various foods, wearing shatnez, engaging in various physical relations, etc.
This concept is very applicable to us in the sense that we often overlook our predisposition for greatness. Hashem created us with elevated souls. We were given all of the inclinations and aptitudes to reach true greatness. Additionally, Hashem gave us the greatest guide to spiritual perfection – the Torah. If we learn to follow its ways and appreciate its systems, we journey forward on the greatest mission of man – the road to perfection.