In his previous bestsellers, Masson has showed us that animals can teach us much about our own emotions—love (dogs), contentment (cats), and grief (elephants), among others. In Beasts, he demonstrates that the violence we perceive in the "wild" is a matter of projection.

Animals predators kill to survive, but animal aggression is not even remotely equivalent to the violence of mankind. Humans are the most violent animals to our own kind in existence. We lack what all other animals have: a check on the aggression that would destroy the species rather than serve it. In Beasts, Masson brings to life the richness of the animal world and strips away our misconceptions of the creatures we fear, offering a powerful and compelling look at our uniquely human propensity toward aggression.