Wow I am glad to see there is a forumn here to discuss this all. I have been reading Ayn Rand's non fiction as well as Peikoffs for about 2 years now. I have a huge issue though that doesn't seem to make any sense to me.
What I want to be able to do is reduce concepts and ideas to thier perceptual roots in order to know if what I "know" is accurate. So I started looking at the definitions that I had for a concept and tried to reduce it. That brought up a problem. First of all it seems that the Genus of a concept is (maybe by it's nature) more abstract than the concept it self.
Take the concept running for example. Using a basic defintition I would say it would look like this:
Genus: an activity
Differentia: where a creature moves quickly through use of it's legs.
Okay so lets say we were trying to reduce running to it's perceptual roots. I would think we would need to look at the terms of the defiinition and reduce those (though I have been since told that is called rationalism). The issue though is that "activity" subsumes running, walking and everything else.
But wait... Don't we need the concepts running, walking, etc to form the concept activity? isn't activity dependant on these concepts? If that is the case does that mean we ignore the the genus? How would reduction work?
This is the issue that i have with the hierarchy of concepts. I have been trying to digest this issue for over a year but it just won't go down... Doesn't make sense.
What do you guys think?
