Charles Darwin

"If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down. But I can find out no such case."

"The belief in God has often been looked at as a mark of weakness but strength of character."

"It seems to me absurd to doubt that a man may be an ardent theist and an evolutionist."

"The main conclusion here arrived at, and now held by many naturalists who are well competent to form a sound judgment, is that man is descended from some less highly organised form."

"I feel sure that I have little natural ability; my power seems to have lain in the quickness with which I understood new subjects and in memory, which enabled me to retain, all that I had once read."

"It is interesting to contemplate the earth covered with the most beautiful productions."

"The truth of the existence of a single Supreme Being is now to me beyond all doubt."

"I cannot persuade myself that a beneficent and omnipotent God would have designedly created parasitic wasps with the express intention of their feeding within the living bodies of Caterpillars."

"When on board HMS Beagle, I was much struck with certain facts in the distribution of the inhabitants of South America."

"Nothing is easier than to admit in words the truth of the universal struggle for life, or more difficult to constantly bear this conclusion in mind."

"The greatest good for the greatest number of beings."

"There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved."

"It is not the strongest of the species that survives, nor the most intelligent, but the one most responsive to change."

"A man who dares to waste one hour of life has not discovered the value of life."

"The love for all living creatures is the most noble attribute of man."

"I am convinced that it is immensely advantageous to keep shifting one's point of view."

"There is a grandeur in this view of life."

"Ignorance more frequently begets confidence than does knowledge."

"It has been said that I fell in love with her as soon as I beheld her."

"The fact that man can close his eyes to a fact does not change the fact."

"Believing is more easy than thinking."

"I have tried lately very hard to believe in Christianity, but I find I cannot."

"The struggle for existence will always take place."

"I feel most deeply that this whole question of creation is too profound for the human intellect."

"The presence of a great mind gradually changes the atmosphere of a room."

"Emma was my greatest companion and support throughout my life."

"I am not the least ashamed of my affections for Emma."

"Small changes accumulate into great transformations."

"The capacity to blunder slightly is the real marvel of DNA."

"It is of the highest importance that we should not underestimate our adversaries."