Our Gemara on Amud Beis discusses the concept that regular sacrifices, be they sin-offerings or voluntary offerings, are under the category of asking God for acceptance or appeasement, unlike a first-born sacrifice, which is inherent and pre-dedicated. There is a subtle difference in language between Rashi and Tosafos, which I believe speaks of a philosophical disagreement.
Rashi explains the idea of sacrifices to achieve appeasement or acceptance as:
הרצאה - אם לכפרה אם לדורון
Acceptance: Either by way of asking forgiveness in a sin-offering or by offering a voluntary gift to God.
Tosafos states it differently:
קדשים דבני הרצאה נינהו. דעולה מכפרת על חייבי עשה כדאמרינן בפרק קמא דזבחים (דף ז: ושם):
Even an Olah sacrifice is intended to appease. It’s function is to achieve forgiveness for neglecting to fulfill a positive commandment, as it states in Zevachim (7b).
It would seem that according to Tosafos the Main function of Olah is to also achieve forgiveness, while according to Rashi it’s main function is to serve as a gift, which thereby can be used as part of a process of forgiveness for violating a positive commandment. (This machlokes can be seen more explicitly in Zevachim 7b, עיין תוד״ה עולה, ורש״י ד״ה עולה היא, ודו״ק )
What is the philosophical root of this? Perhaps Rashi holds that neglecting a positive commandment cannot intrinsically be a “sin”, since literally nothing was transgressed, therefore there is no inherent need for forgiveness. Rather, The Olah is re-establishing the connection to God. While Tosafos holds that a sin of omission is indeed a sin, and needs forgiveness in much the same manner as a violation of a negative commandment.
Another way of looking at this dispute is to consider what is the ideal way to achieve forgiveness for sins of omission, be that as it may be considered. According to Rashi, the main point is to reconnect through the devotional act of the Olah, which then indirectly of course achieves the forgiveness. According to Tosafos, forgiveness must be achieved first and then reconnection.
Translations Courtesy of Sefaria, (except when, sometimes, I disagree with the translation .)