The human foot is a masterpiece of engineering and a work of art.

Every man at three years old is half his height

Those who are in love with practice without knowledge are like the sailor who gets into a ship without rudder or compass and who never can be certain whether he is going. Practice must always be founded on sound theory, and to this Perspective is the guide and the gateway; and without this nothing can be done well in the matter of drawing.

The eye is the window of the human body through which it feels its way and enjoys the beauty of the world.

The cat is nature's masterpiece.

It should not be hard for you to stop sometimes and look into the stains of walls, or ashes of a fire, or clouds, or mud or like places, in which...you may find really marvellous ideas.

The knowledge of the past times and of the places of the earth is both an ornament and nutriment to the human mind.