- Part of a Corpse: the part creates tumah because it is part of a corpse. In this case we require a quantitative measure for it to be a significant enough part to be a source of Tumat Met.
- Represents the Entire Corpse: the part represents a whole corpse. Here, conditions for the part to be a source of Tumah are qualitative in nature.
General Nafka Minot
Rav Wolf brings two general cases from Rav Aharon Lichtenstein(שיעורי הרא"ל טהרות) as to how this distinction may play out halachically:
For one, there is the issue of combining. If we’re dealing with part of a corpse and thus a quantitative measure, then two parts, individually considered too small, can combine to create a larger one that does produce Tumah. If, however, we’re concerned with a part that qualitatively represents a whole corpse, then insignificant parts can’t combine into a significant one.
2. Nothing Significant Left
There are cases where no significant portion of the corpse is left and yet, what is left carries tumat met. These cases must be understood as qualitatively representing the entire corpse, rather than being a quantitative part of the corpse.
Rav Wolf applies this distinction to many different cases. Here's the abbreviated version:
- כזית בשר מן המת- a qualitative or quantitative measure?
- רביעית דם- a qualitative or quantitative measure?
- מת שנשרף ושלדו קיימת- apparently qualitative according to Hachamim
- דם קטן שיצא כולו- R. Akiva that says it’s tamei must consider it qualitative
- מלוא טרוד רקב(rotted remains)- apparently qualitative
- חרב כחלל- apparently qualitative if Nazir must shave for touching it