Can Animals Be Taught Concepts?

ID critic and University of Waterloo computer scientist Jeffrey Shallit takes exception to my observation in a recent post that animals lack the capacity for abstract thought. Abstract thought is the ability to conceive of universals -- mercy, justice, mankind, logical and mathematical relationships, and the like. It is an immaterial power of the mind, and only human beings are capable of abstraction.

I wrote:

Human beings have mental powers that include the material mental powers of animal...