PHIL 2501 Lecture Notes - Lecture 17: Twin Earth Thought Experiment, Indexicality, Natural Kind
12 Apr 2016
School
Department
Course
Professor
Document Summary
The gist of putnam"s atack on the ka: Ex: intension goes to (via ixing) only one extension per intension, putnam"s problem says: One intension (water) ixes to 2 extensions! Extension 2 (xyz: an intension ixes extension, intensions are in the head, they are concepts, concepts are in the head. Review of twin earth: possible world example, twin earth is exactly like ours except water = xyz versus h2o, so they use the same sound ( water ) to represent a diferent thing. Known by chemical analysis: goes further by saying, lets go back 50 years, before chemical analysis, new person arrives on twin earth; goes through same process. But no one knows h2o or xyz composiions. So the meaning of water is just the same in both worlds. Water"s meaning on earth = meaning on twin earth. Putnam says: water does not mean the same thing. On twin earth water is and means xyz: same on earth, but h2o.
