Chapter 1, Tutorial 4
Complex Arguments and Tree Diagrams


In this tutorial, we look at arguments that are slightly more complicated and more realistic. It's best to see what's in store with an example.


Dark chocolate not only tastes great but is healthy.

So, we have an argument. Let's give it our standard diagram:

Dark chocolate tastes great (to many humans).
Dark chocolate is healthy (for humans).       
Dark chocolate is a good food (for humans).

But, if you're thinking rather than just salivating, you might wonder:



































































Let's look at some of the basics of these more complex tree diagrams. To get started, which of the following arguments have premises that independently support the conclusion?

  1. One reason to believe that the evolution of species is real is a look at the fossil record. Another reason is the evidence from the laboratory on speciation in fruit flies.
  2. All reindeer are hoofed beasts. No hoofed beasts are bats. So, no reindeer are bats.
  3. I can hear music coming from inside. And there are several lights on. So, someone is probably at home.