‏עקרונות התלמוד

Question 1

‏חזקה

Answer 1

‏חזקה —
literally, “strong”) usually refers to the default assumption; i.e., what is assumed until there is evidence to the contrary. For example, if one is known to have owned real estate, it is assumed that he still owns it until proven otherwise. However, with movable items, the chazakah lies with whoever currently has the item in his possession, not with the one who had previously owned it.
‏This principle also applies in ritual law. For example: Food known to be kosher maintains its status until there is evidence to the contrary. Also, one who engages in acts done only by Kohanim is assumed to be a kohen himself, until proven otherwise.

Source:
According to one opinion in the Talmud, the principle of chazakah has a Biblical source in Leviticus 14:38, which discusses the case of tzaraat in a house. After the priest had examined the plague-sore and found it to be of a certain size, he locked the house for seven days, at the conclusion of which time another examination was made. “Is it not possible that while he was locking the door the plague-sore diminished in size? Since, however, Scripture takes no notice of this, it must be because it presumes that the plague remained in the state in which it was first found by the priest; Scripture teaches us here the principle of presumption”.However, some of the amoraim rejected this derivation, and instead held that chazakah is a Law given to Moses at Sinai.

Question 2

דאורייתא

Answer 2

Of the Torah. I.e. scriptural. if it was given with the תורה שבכתב.

Question 3

דרבנן

Answer 3

דרבנן - מדברי סופרים

“of our rabbis,” if it is ordained by the rabbinical sages (תורה שבעל פה)

Question 4

קל וחומר

Answer 4

literally “lenient and strict”. derives one law from another through the following logic: If a case that is generally strict has a particular leniency, a case that is generally lenient will certainly have that leniency. The argument can also work in reverse, and also in areas where lenient or strict might not be precisely applicable.

Question 5

מיגו

Answer 5

A migo (Aramaic: מיגו, literally “out of” or “since”) is an argument for a defendant that he ought to be believed regarding a certain claim, because he could have made a different claim which would definitely have been believed.

For example, if someone admits to having borrowed money and claims to have paid it back, he is believed because he could have claimed that he never borrowed the money in the first place (absent other evidence for the loan).