In lieu of commentary to the first three parshiyot of Sefer Vayikra, the philosophic parshan Rabbi Yosef Ibn Caspi writes the following:
I have already indicated several times in this commentary, and in my Sefer Hasod and Sefer HaMashal, that my character is to strongly prefer brevity in all cases. Therefore, when I saw that this parashah and many that follow it revolve around the making of offerings and sacrifices – which it is known that Mosheh Rabbeinu of Blessed Memory wrote in his book under necessity and coercion, because the Name has no wish for wholly burnt sacrifices and offerings, rather it was the necessity generated by the practice of nations at the time that brought them to this . . .Therefore I will let this parashah be, and Parashat Tzav, and Parashat Shemini . . .
Ibn Caspi here is following the simplest (but I think incorrect) interpretation of Rambam’s Guide to the Perplexed 3:32.
Many things in our Torah are said in expression of the same type of management . . . For as it is not possible to go from one to the opposite extreme in one shot, therefore it would not fit the nature of humans to abandon all their habits in one shot. Now Hashem sent Mosheh Our Teacher to make us into a kingdom of priests and a holy nation through knowledge of Him may He be exalted . . . and to concentrate solely on His service . . . and the universally recognized and habitual nature of service then, as well as the general form of service in which we had been raised, was the sacrifice of various animals in the temples in which the images stood, and bowing to those images, and placing incense before them . . . Therefore His wisdom, may He be exalted, and His management, which is evident with regard to all His creations, did not require that He command us to abandon all those forms of service and utterly disfavor and eliminate them, because that would not have been something the nature of human beings, which always finds its rest in habit, could accept . . .
On this understanding, sacrificing has no inherent religious value. This position can be seen as theologically scandalous because it makes part of Torah seem contingent. It also has difficulty accounting for Rambam’s exhaustive explication of the laws of sacrifices in his Mishneh Torah.
Ibn Caspi himself may offer a more complicated rationale in his commentary to Devarim 12:31:
“Do not do so to Hashem your G-d” – Had Moshe been able to prevent them from sacrifices absolutely, since they were done to the gods of the nations, Hashem would have wanted this, but because he was not able to eliminate them at the root, he at least eliminated the shameful branches to the extent possible, such as the burning of children . . .
The implication here is that sacrifice was originally a fine mode of worship. However, it was corrupted by becoming the standard form of idolatrous worship. G-d would therefore have preferred to eliminate it, just as the Torah banned the erection of matzeivot even though this was a legitimate mode of worship for the Avot. Instead, because a complete ban was not psychoculturally plausible for Am Yisroel, He distinguished between modes of sacrifice that are morally better or worse, and eliminated the worst.
This model raises the question of whether a further pruning might be possible in an ideal world, while still leaving the fundamental concept of sacrifice intact. Malakhi 3:4, the opening verse of the haftorah for Shabbat haGadol, is often cited as the basis for one possibility.
“then the minchah of Yehudah and Yerushalayim will be as sweet to G-d as in days of yore and ancient year”.
Minchah can refer specifically to offerings made from grain, and Rav A.Y. Kook suggested that perhaps only minchahs would be offered in the Third Temple; there would be no animal sacrifice. This suggestion appeals to those who find the killing of animals for religious purposes distasteful. However, minchah is also a generic term for gifts or offering.
Vayikra Rabbah 9:7 offers a selection based on purpose rather than object: “All sacrifices (and prayers) will be eliminated in the Coming World, except for the Thanksgiving sacrifice (and prayers)”. The simplest understanding of this is that most sacrifices seek to atone for sin, and most prayers express the desire for something we lack. In the Coming World, both sin and lack will cease, and our relationship to G-d will be framed entirely by gratitude. But one can also understand it as making the claim that sacrifice is easier to justify when it expresses gratitude than when it expresses fear.
All these approaches really beg the core question: Why is the act of sacrifice so powerful psychologically? Why do human beings naturally express themselves religiously through sacrifice, whether they are expressing fear or gratitude? In an age without a Temple, it can be difficult to relate to this question; and yet it seems to me that Ibn Caspi is correct that Sefer Vayikra can be meaningful only if we address it.