The Ins & Outs Of Nezek

Let me clarify a bit more.

The case of two posh’im for a nezeck is when one guy didn’t watch his dog and another didn’t watch his chararah. The dog took the chararah and burned a gdish. Both are chayav. The gemerarah’s case, though, is that the gdish belongs to the chararah man. Here, when both are poshea, the owner of the dog pays half. The owner of the gdish is not gramah to his nezeck but he was rather mazik himself. That is why it’s different from the guy who gets his kad smashed.

Moreover, tosphos say that the owner of the chararah did not have to watch it from being nizik, by being eaten, but he does have to watch it from being mazik. Even though the hezek is to himself, he is not a nizik, but a mazik to himself, since he is responsible for a mayseh hezek. Any mayse hezeck is a mazik, whether or not you do it to yourself.

A nizik is when someone does a a mayse hezek to you, and you don’t do any mayse hezek to yourself. Even by bor that the nizik does the mayse of going into the bor, he is not doing a mayse hezek to himself but a mayse nizik to himself.

Moreover, tosphos says that even if the man who smashed the kad must watch where he’s going in regard to not smashing the kad, he still does not have to watch where he’s going in regard to getting hurt by the kad. Tosphos says you have to be more careful not to be mazik. We already saw that being mazik yourself is also called mazik. Tosphos over there also says you need to be more careful not to be mazik, and there you are mazik yourself. By bor, however, you are not mazik yourself, but nizik yourself.

Nonetheless, since by bor your nizik yourself, if you do so stupidly, we say ihu diazik anafshei. According to Rashba”m this applies even not to bor, but according to others it only applies to bor since your nizik yourself.