Nature never breaks her own laws.

Instrumental or mechanical science is the noblest and above all others, the most useful.

The grave will fall in upon him who digs it.

It is useful to constantly observe, note, and consider.

I roamed the countryside searching for the answers to things I did not understand. Why shells existed on the tops of mountains along with the imprints of coral and plant and seaweed usually found in the sea. Why the thunder lasts a longer time than that which causes it and why immediately on its creation the lightening becomes visible to the eye while thunder requires time to travel. How the various circles of water form around the spot which has been struck by a stone and why a bird sustains itself in the air. These questions and other strange phenomena engaged my thought throughout my life.

Whoever despises the high wisdom of mathematics nourishes himself on delusion and will never still the sophistic sciences whose only product is an eternal uproar.

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.