Man has much power of discourse which for the most part is vain and false; animals have but little, but it is useful and true, and a small truth is better than a great lie.
Leonardo da VinciAvoid the precepts of those thinkers whose reasoning is not confirmed by experience.
Leonardo da Vinci... we might say that the earth has a spirit of growth; that its flesh is the soil, its bones the arrangement and connection of the rocks of which the mountains are composed, its cartilage the tufa, and its blood the springs of water.
Leonardo da Vinci