After a lifetime of scientific discoveries, world-famous physicist Stephen Hawking passed away Wednesday morning at the age of 76.
Hawking was widely revered for both leading modern day understanding of the universe and physics as well as surviving ALS, a life-threatening disease, for over 50 years.
Hawking received his undergraduate degree in physics at the University of Oxford and went on to earn his Ph.D. at the University of Cambridge (where he most recently worked as a professor).
In his lifetime, Hawking spoke about striving for success and happiness as well as the importance of gender equality. Here are a few of his most powerful quotes:
'While there's life, there is hope'
Hawking was diagnosed with ALS around the age of 21 as he was beginning his Ph.D. program at Cambridge.
"At first I became depressed. I seemed to be getting worse pretty rapidly. There didn't seem any point in working on my Ph.D. because I didn't know I would live long enough to finish it," Hawking said in a message for his 70th birthday celebration, as The Guardian reported in 2012.
Despite his worsening condition, getting engaged to his college sweetheart lifted his spirits. It made made him realize, "if we were going to get married, I had to do a job and finish my Ph.D. I began to work hard and I enjoyed it."
Hawking reiterated his appreciation for life at the Hong Kong University of Science and Technology in 2006. In response to a question about a paralyzed accident victim in Hong Kong, Hawking said the person should have the right to choose whether or not to continue living. "However bad life may seem," he explained, "there is always something you can do, and succeed at."
"While there's life, there is hope," Hawking added.
'Remember to look up at the stars'
On several occasions, Hawking advocated for living the best life you can.
"Remember to look up at the stars and not down at your feet," Hawking said in the birthday message. "Try to make sense of what you see and about what makes the universe exist. Be curious."
Hawking also refused to allow his disability to hold him back physically, mentally or spiritually.
"I don't have much positive to say about motor neuron disease. But it taught me not to pity myself, because others were worse off and to get on with what I still could do," Hawking told The New York Times. "I'm happier now than before I developed the condition. I am lucky to be working in theoretical physics, one of the few areas in which disability is not a serious handicap."
He also advised that other people suffering from serious illnesses to not "be disabled in spirit."
'I have always supported women's rights'
In an interview on Good Morning Britain in 2017, Hawking expressed his views on gender equality and feminism.
"It is not scientific proof of gender equality that is required, but general acceptance that women are at least the equals of men or better — this is coming," Hawking said. "If we factor in high power women in Europe as well, such as Angela Merkel, it seems we are witnessing a seismic level for women to reach the high level in politics and society."
"But there still may be a gap between those women reaching high public status and those in the private sector. I welcome the signs of women's liberation," Hawking added.
When asked frankly if he was a feminist, Hawking said, "Yes. I have always supported women's rights."
'I'm happy if I've made a small contribution'
After building on the scientific findings of Albert Einstein, Hawking said he celebrates his wins and is optimistic about what mankind has achieved.
"Our picture of the universe has changed a great deal in the past 40 years and I'm happy if I've made a small contribution," Hawking said, according to The Guardian.
"The fact that we humans – who are ourselves mere collections of fundamental particles of nature – have been able to come this close to an understanding of the laws governing us and our universe is a great triumph," he added.
Like this story? Like CNBC Make It on Facebook.