All our knowledge has its origin in our perceptions - Leonardo da Vinci

"Make your work to be in keeping with your purpose"

"Our life is made by the death of others."

"The acquisition of knowledge is always of use to the intellect, because it may thus drive out useless things and retain the good. For nothing can be loved or hated unless it is first known."

"Wisdom is the daughter of experience"

"As a well spent day brings happy sleep, so life well used brings happy death."