“Speak to Bnai Yisrael and say to them the following: When a person from among you offers a sacrifice to Hashem, if it is an animal sacrifice, it should be taken from the cattle or the flocks of sheep or goats.” (VaYikra 1:2)
Much of Sefer VaYikra deals with the laws regulating sacrifices. The idea of animal sacrifice presents a challenge for many of us. The Torah was given to us by Hashem as a revealed truth. It is designed to elevate humanity. Its mitzvot establish the highest standards for human conduct. The Torah gives us an advanced system of justice and jurisprudence. It describes standards of social responsibility and charity. The Torah derides superstition primitive religious attitudes. So, it seems quite remarkable that a system devoted to the elevation of humanity beyond paganism and primitivism endorses and requires animal sacrifice. How can we reconcile this institutionalization of animal sacrifice with the progressive attitudes of the Torah?
Generally Maimonides is acknowledged as offering the most compelling response to this issue. His response is significant not only in its treatment of this issue but also in its treatment of related issues.
Maimonides begins by stating an assumption that is fundamental to his approach to understanding sacrifices. He explains that the wisdom and intelligent design of Hashem is evident in the complexity of the universe. This same wisdom is manifest in Hashem’s providence over humanity and Bnai Yisrael. This means that Hashem considers human nature in His interaction with humanity. One element of human nature that Hashem considers is that human behaviors and attitudes cannot be suddenly, radically altered.
Based on this assumption, Maimonides offers a novel approach to explaining animal sacrifice. He explains that Hashem’s objective in His relationship with Bnai Yisrael was to develop the people into a nation devoted to His service. Hashem chose to not forsake sacrifice as one of the forms of service. This was because sacrifice was an established form of worship. Abandonment of sacrifice as a form of worship would have represented a radical change of attitudes and behaviors. In other words, in order to achieve the goal of forming a nation devoted to Hashem a concession was made to human nature. The traditional, accepted form of worship was preserved.
Maimonides continues with an amazing analogy. Imagine our reaction if Hashem were to tell us to abandon prayer as a form of worship. Instead, we are to serve Hashem through thought alone. We would not know how to serve Hashem without some available mode of material expression. Sacrifice played an analogous role in the minds of Bnai Yisrael. Therefore, Hashem chose to not abandon it.
However, this created a dilemma. Sacrifice was associated with idolatry. Hashem had to reform sacrifice and strip it of all idolatrous elements.
In order to reform sacrifice, it is highly controlled and structured. This intensive attention to detail assures that all elements of idolatry are removed and not permitted to reenter sacrificial service.
In essence, it seems that Maimonides acknowledges that animal sacrifice does not represent an ideal form of worship. In fact, he seems to accept that this form of worship is a remnant from more primitive times and cultures. Nonetheless, he argues that the Torah – in recognition of the limitations of human nature – chose to preserve this ancient form of worship.
Next, Maimonides discusses a related question. He asks why Hashem did not merely require the ultimate level of service. Certainly, He can instill within us the ability to meet this requirement! Maimonides’ answer has two parts.
First, Maimonides shows that Hashem typically does not resolve human shortcomings through altering human nature. For example, when Bnai Yisrael were brought out of Egypt, Hashem did not lead them to the land of Israel by the most direct route. This was because the nation was not yet prepared to battle mighty nations. Hashem did not alter the people’s nature. Instead, He accommodated it.
Second, Maimonides explains this practice of Hashem on a deeper level. Although Hashem can alter human nature, this is not his method of relating to Bnai Yisrael. Instead, He gave us the Torah and sent us prophets to guide us and help us improve ourselves.
Finally, Maimonides assets that a carefully study of the Torah and the Prophets supports his thesis. He identifies various passages that support his explanation of sacrifices. Maimonides also points out that the offering of sacrifices is restricted. Other forms of worship are not subject to as many restrictions. For example, one can pray virtually anywhere. No Kohen is required to participate. This encourages a de-emphasis of sacrifice and a reorientation to other more meaningful forms of worship.
Maimonides’ explanation of sacrifices provides a compelling answer to a difficult question. The Torah – the Written Law – describes the laws governing sacrifices in great detail. The Written Law deals other important mitzvot much more concisely. For example, nowhere does the Written Law provide a detailed or even general description of teffilin. Similarly, the Written Law does not precisely define type of activity that is prohibited on Shabbat. The Written Law provides a general statement and the details are provided by the Oral Law. This same pattern is followed in the Torah’s treatment of most other mitzvot. This is not the case in regard to sacrifices. Sacrifices are described in elaborate detail in the Written Law. The only other area that receives the same meticulous treatment is design and structure of the Mishcan. Why does the Torah treat these two areas in a manner that is starkly inconsistent with its usual approach? Maimonides’ thesis regarding sacrifices provides a response.
According to Maimonides, the Torah created its system of sacrifices in response to two considerations. First, it would have been impossible to develop a new religion that completely abandoned traditional, deeply rooted forms of worship. So, sacrifices were preserved within the Torah. Second, the Torah was compelled to regulate and structure sacrifices in order to “sanitize” them and strip them of any element of idolatry. But it must be added that this structuring and regulating of sacrifices did not just eliminate all elements of idolatry. These same detailed laws prevented the restoration of idolatrous practices and traditions into the Torah’s system of sacrifices. The Torah’s concession to human nature in allowing sacrifices is a dangerous one. It allows an institution identified with idolatry to continue to exist. It responds to the danger that this institution become corrupted and degenerate back into idolatry though careful regulation. The Torah deemed these regulations so important that it was unwilling to relegate them to the Oral Law. These regulations must be well known and their importance must be fully appreciated. This is accomplished by placing these laws in the Written Torah.
 Rabbaynu Moshe ben Maimon (Rambam / Maimonides) Moreh Nevuchim, volume 3, chapter 32.  Rabbaynu Moshe ben Maimon (Rambam / Maimonides) Moreh Nevuchim, volume 3, chapter 32.