1.Science must not be a selfish pleasure.Those who have the good fortune to be able to devote themselves to scientific pursuits must be first to place their knowledge at the service of humanity. Le. Those who have the opportunity to devote themselves to scientific pursuits must first put service to mankind first in the knowledge they pursue. 2.True science teaches us above all to doubt and to know that we are ignorant.True science teaches us above all to doubt and to know that we are ignorant. Science allows us to abandon superstition and understand our ignorance. 3. Science is built of facts the way, a house is built of bricks; but an accumulation of facts is no more science than a pile of bricks is a house. Based on facts, a house is made of bricks; but the accumulation of facts is not more scientific than laying bricks to build a house.