More on R. Ishmael and R. Akiva.
The disagreements between the school of R. Ishmael and R. Akiva  are not arbitrary but based on different approach to interpretation. In general, R. Ishmael and his school used definite rules of interpretation and applied them only when there was a 'hermeneutical marker', an indication within the verse that the Torah intended a derash . Thus, for example, a gezerah shavah (use of same words) can be used only if there exists a redundancy, an unneeded or 'extra' repetition of the term in one or both verses. This is called mufneh.
R. Ishmael "hears" the intended, under the surface meaning of a verse and grasps its directions to the reader. He always uses the terminology "Shomea ani". You must hear and comply. When the verse provides a marker, it is it and not a human interpreter that interprets. R. Ishmael calls such a situation 'maggid or omer lecha hakkasuv'- the verse tells you. When there is no such marker, R. Ishmael objected strongly to making a derash. R. Ishmael uses klal and perat, which are fairly close to a careful literal meaning . R. Akiva uses ribbuy and miyut, which is more technical and less apparent. R. Eliezer and R. Akiva, on the other hand, used fairly arbitrary devices such as ribbuy and miyut and do not ask for a hermeneutical marker. Passages from R. Akiva's school use expressions that place the power to interpret in the hands of the human interpreter. They use terms such, "Yachol" - I might think to say so…but there is ground to say differently. In the following passage R. Eliezer uses a ribbuy and R. Ishmael objects.
And a garment of wool or linen that contains tsaraas…
I only know a garment of wool or linen, how do you know to include garment of kelaim? Talmud teaches "and garment'. I know only when one of the types is kelaim in a part of a garment; how do I know when it is throughout the garment or about when one kind is throughout and the other only in a part? Talmud teaches: 'And the garment'. I know only when it is a garment in which a kelaim of three by three cubits was woven, what about a garment in which there is less than three by three? Talmud teaches: "And the garment". I only know a garment that has space for the tsaraas to spread. What about when there is no additional space? Talmud teaches: "And the garment". These are words of R. Eliezer.
R. Ishmael said to him: You are saying to the verse (hakkasuv): "Be silent until I interpret". R. Eliezer said to him: "Ishmael, you are a mountain palm (that does not bear fruits suitable for Bikkurim, see Bikkurim 1,3)".
It may be suggested that R. Eliezer, viewed by his contemporaries as Sinai (Sukka 27a), as "a cistern that does not loose a drop (Avos,2)", as one who never taught anything that he did not hear from his teachers (Sukkah 27b), viewed Derash as something that merely backed up received traditions. As such, he did not need to be overtly restricted by literal meaning. R. Ishmael on the other hand, often utilized the principles of interpretation to derive new laws; as such, he would allow interpretation only when the verse itself commanded: "Darshen me!"
In support of this idea we may adduce a Sifri in Parshas Chukkas, which suggests that R. Ishamel also occasionally used ribbuy.
The cow shall be burned as he watches - its hide, its blood on its intestines(Numbers 19,5). A ribbuy that follows another ribbuy is to exclude (lemaet) - these are words of R, Ishmael.
Mishna Shevuos 2, 5 may contain another instance of R. Ishmael using a ribbuy. In addition, we find in Bechoros 51a that Rebbi, who usually uses 'klal and prat' occasionally uses ribbuy and miyut. In Bechoros, he uses it on the basis of its use by "tanna d'bei R. Ishmael".
Might it be that R. Ishamel himself resorts to ribbuy when he possesses a tradition that for which no hermeneutical marker can be located?
The distinction between methodology of different Tannaim allows as to bring a sharper focus into our study of Halachic midrash and to its citations within the Talmud.
1 R. Ishmael studied under R. Nechunia ben Hakone (Shevuos 26b) and his school includes R. Yonatan, while R. Akiva's method appears to have been inherited from R. Eliezer and carried forward by most of the enxt generation of the Tannaim, who were his students as well as R. Yoshia.
2 For a book length treatment of this point, seee Azzan Yadin, Scripture as Logos: R. Ishmael and the origins of Midrash,, Univ.Penn. Press, 2004.
3 When there is a general statement of principle followed by particular example, you allow the general to be defined by the particular. For example, "from animals , from cattle, from sheep you shall bring your offerings (Leviticus 1, 2)". Animal is a general category, for wild animals are also included under the rubric of 'animals', such as when says, "These are the animals that you shall eat - cow, sheep (domesticated)…ram and antelope (wild) (Deuteronomy 14, 4)". The verse proceeds with "from cattle, from sheep" - this is a particularization for it excludes wild animals. The overall meaning is that the general term "animals" that is used here includes only those animals that are similar to those in the particularizing clause - in other words, only domestic animals. Consequently we interpret the term "animals" in the beginning of this verse as if it excludes wild animals.
Fifth rule: Specific followed by general, such as, "Do not just watch the donkey of your brother or his sheep when it was lost…return it to your brother…and so shall you do to his donkey and so shall you do to his raiment and so you shall do to all that your brother has lost…(Deuteronomy 22, 4)". Ox, sheep, donkey and raiment are specific and "all that your brother has lost" is general, broadening the category beyond the specific examples mentioned, to any kind of thing that is lost.
Sixth rule: General, then specific, then general (again) - you first limit the original broad category and then expand it again. (In conclusion, the general is somewhat limited but it is broader than the specific examples found in the verse). For example, "If a man gives to his fellow silver or vessels to watch and it is stolen from that man's house… if the thief was not discovered, the man in whose house it was shall approach the judges (to swear) that he did not send his hand out (to use) his fellow's property (Exodus 22, 8). It continues, "For any matter of negligence" - this is a general category. "For ox, for donkey, for sheep, for raiment" - this is specific. "For any matter that is lost" - general (again). The verse enunciated specific examples to show us that just like the specific examples are in a class of movable entities that have a monetary value, so also the general category include only what is movable and had monetary value (but not restricted to only those examples specified by the verse).