Professor Stephen Hawking's revealed how he has always tried to 'lead as full a life as possible,' in response to a plea for inspiring message.
Other A-list stars, including actor Sir Ian McKellen, athlete Jessica Ennis-Hill, actor Sir David Jason and sailor Dame Ellen MacArthur also shared some words of wisdom.
The famous faces put pen to paper for Simon Rhodes after he asked them for encouraging quotes to spur on staff at his legal firm.
The first to arrive was from the 73-year-old scientists and author, who suffers from motor neuron disease.
Professor Hawking wrote: 'I have always tried to overcome the limitations of my condition and lead as full a life as possible. I have travelled the world, from the Antarctic to zero gravity.'
He accompanied his message with a thumb print.
Mr Rhodes, 46, from Southampton, Hampshire, fired off 25 letters to some of the most famous names in the country and in total 18 replied.
In return, he made a £100 donation to a charity of the celebrity respondents choosing.
Mr Rhodes, who is the managing partner at law firm Trethowans, said: 'I was pleasantly surprised that so many came back and it's the little bits where they have gone over and above.
'But the one where I sat down and held it because I didn't expect to get it was Stephen Hawking. It made me smile the most.
Mr Rhodes came up with the idea last year to motivate the 150-strong staff but wanted to use words that were not 'corporate speak'.
He said: 'We all look at these motivational messages like 'sell more' and 'buy more' but they can have the opposite effect.
'I wanted something that would motivate and the only way I thought I could do that was not by having our words.
'So I dug out the quotes and wrote to them all saying I was trying to motivate the next generation of our staff.
'I told them I have read what they have said and how I thought it was motivational and said that if they were able to send a signed photograph with a message to our staff at Trethowans I will give £100 to their favorite charity.'
The quotes and photographs of each of the celebrities have now been split between their new office in Southampton and a second office in Salisbury, where they have been hung on the walls of the staff seating area.
Chelseamanager Jose Mourinho: 'Pressure? What pressure? Pressure is millions of parents around the world with no money to feed their children. There is no pressure in football.'
Actor Sir Ian McKellen, with a message saying 'Greetings from Middle Earth', said: 'All we have to do is decide what to do with the time that is given to us.'
Ex-Footballer Matt Le Tissier: 'If you haven't anything difficult to do today, then what's the point in getting up! Meet things head on, even the tough things'
Arsenal manager Arsene Wenger: 'Nobody has enough talent to live on talent alone. Even when you have talent, a life without work goes nowhere.'
Athlete Jessica Ennis-Hill: 'Training is full on. Some days I really don't want to get out of bed and hit that track again. Sunday and Monday morning sessions are always horrible, but who really looks forward to going to work on a Monday Morning?'
Chef Heston Blumenthal: 'I was determined that if I failed, it wouldn't be through lack of effort'
Professor Stephen Hawking: 'I have always tried to overcome the limitations of my condition and lead as full a life as possible. I have travelled the world, from the antarctic to zero gravity'
Actor Sir David Jason: 'I've done my fair share of waiting on tables in restaurants, cleaning cars, whatever. I was even an electrician at one time, and I've done my fair share of decorating too*.. but slowly my fortunes changed'