This book explores what Thomas Aquinas said about the importance of animal side of human nature in relation to such non-animal pursuit as contemplation. The author shows how sensory perception, emotional responses and the feeling of delight - all of which, says Aquinas, belong to the animal side of human nature - guide human contemplation of eternal truths. We contemplate because we are naturally inclined to seek knowledge, to desire truth. According to Aquinas, our basic inclinations, appetites, love and desire, direct us towards our proper good, towards our ends, in accordance with our nature. And when we attain our end, we experience delight. That scheme applies to our pursuit of any goods, whether sensible objects, like food, or the intellectual goods, like truth. Thus the operations of the intellect, like contemplation, cannot be divorced from the operations of the animal aspects of human nature. That composite nature of a human being - a rational animal - persists even in heaven.