Institutio Oratoria

And in truth that god, who was in the beginning, the father of all things and the architect of the universe, distinguished man from all other living creatures that are subject to death, by nothing more than this, that he gave him the gift of speech.

For as regards physical bulk, strength, robustness, endurance or speed, man is surpassed in certain cases by dumb beasts, who also are far more independent of external assistance. They know by instinct without need of any teacher how to move rapidly, to feed themselves and swim.

Many too have their bodies clothed against cold, possess natural weapons and have not to search for their food, whereas in all these respects man's life is full of toil. Reason then was the greatest gift of the Almighty, who willed that we should share its possession with the immortal gods.