Zevachim 3 - He Noted a Contradiction and Resolved It
Rava noted another contradiction: Rav Yehudah said in the name of Rav that a sin offering slaughtered for the sake of burnt offering is invalid, but if one slaughtered it for the sake of regular, non-sacrificial meat, then it is valid. We see from here that the intent for another offering invalidates the sin offering, but the intent for something that is not an offering at all does not have any adverse effect.
On the other hand a Get, written not for the sake of one's wife, but for the sake of a different women (provided that they have the same names) is invalid. Even if it is written for the sake of an idolatress, to whom the laws of Jewish marriage do not apply, the Get is still invalid. Thus, in the case of Get the intent for something completely different does invalidate it. Why is this difference?
He answered that in the case of divorce, if one takes the idolatress out of the picture, this Get is not intended for his wife and is thus invalid, but with sacrifices, if you take the intent for non-sacrificial meat out of the picture, it becomes no intent at all, and such sacrifices are valid.
Art: Piero della Francesca - Portraits of Federico da Montefeltro and His Wife Battista Sforza