Appeals to readers’ values. Effective arguers try to appeal to readers’
values and emotions. Both MacKay and Lessig appeal to basic values —
MacKay to the value of compassion, both writers to the value of fairness.
These are deeply held values that we may not think about very much and
as a result may see as common ground we share with the writers. And
some of MacKay’s evidence appeals to emotion — her descriptions of people
dying from kidney disease and of poor people selling their organs are
likely to evoke an emotional response in many readers.