Because we care about what we understand, and we identify with it personally. Understanding is used also to mean compassion. When someone demonstrates a lack of human understanding, we say that they are behaving robotically, like a machine, etc. Questions like, "How do you know you are conscious?", or "How do you know that you feel?" are sophistry. How do you know that you can ask that question? Craig -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to email@example.com. Visit this group at http://groups.google.com/group/everything-list?hl=en. For more options, visit https://groups.google.com/groups/opt_out.