Albert Einstein

“Once you can accept the universe as matter expanding into nothing that 

is something, wearing stripes with plaid comes easy.”―Albert Einstein

"Brilliant physicist, proponent of peace, debater of science and spirituality, champion of kindness." These are just a few of the words Maria Popova wrote about the renowned scientist.

Made famous by the equation E=mc², Albert Einstein was never confined to the four walls of a laboratory. Unlike the common notions of what scientists are, he was one with a heart--and, in every way, he made this evident in his works. His pensive yet cheery disposition is considerably an aspect of his personality that he treasured as much as his scientific achievements.

Included in Posterity: Letters of Great Americans to Their Children, Albert's letter to his son, Hans, speaks of his affection as a father and his view on life and occupation:

My dear Albert,

Yesterday I received your dear letter and was very happy with it. I was already afraid you wouldn’t write to me at all any more. You told me when I was in Zurich, that it is awkward for you when I come to Zurich. Therefore I think it is better if we get together in a different place, where nobody will interfere with our comfort. I will in any case urge that each year we spend a whole month together, so that you see that you have a father who is fond of you and who loves you. You can also learn many good and beautiful things from me, something another cannot as easily offer you. What I have achieved through such a lot of strenuous work shall not only be there for strangers but especially for my own boys. These days I have completed one of the most beautiful works of my life, when you are bigger, I will tell you about it.

I am very pleased that you find joy with the piano. This and carpentry are in my opinion for your age the best pursuits, better even than school. Because those are things which fit a young person such as you very well. Mainly play the things on the piano which please you, even if the teacher does not assign those. That is the way to learn the most, that when you are doing something with such enjoyment that you don’t notice that the time passes. I am sometimes so wrapped up in my work that I forget about the noon meal. ...

Be with Tete kissed by your

Papa.

Regards to Mama.

The Dalai Lama

The Dalai Lama's good cheer is probably his most intriguing characteristic. In contrast to the austere, implacable features common among religious figures, the Dalai Lama does not hesitate to exhibit joviality.

Here's an excerpt from the Dalai Lama's book, "My Spiritual Journey," where he shares his thoughts on laughter and compassion:

Of course problems are there. But thinking only of the negative aspect doesn’t help to find solutions and it destroys peace of mind. Everything, though, is relative. You can see the positive side of even the worst tragedies if you adopt a holistic perspective. If you take the negative as absolute and definitive, however, you increase your worries and anxiety, whereas by broadening the way you look at a problem you understand what is bad about it, but you accept it. This attitude comes to me, from my practice and from Buddhist philosophy, which help me enormously. 

...

If we are content just to think that compassion, rationality, and patience are good, that is not actually enough to develop these qualities. Difficulties provide the occasion to put them into practice. Who can make such occasions arise? Certainly not our friends, but rather our enemies, for they are the ones who pose the most problems. So that we truly want to progress on the path, we must regard our enemies as our best teachers.

For whoever holds love and compassion in high esteem, the practice of tolerance is essential, and it requires an enemy. We must be grateful to our enemies, then, because they help us best engender a serene mind! Anger and hatred are the real enemies that we must confront and defeat, not the “enemies” who appear from time to time in our lives.

More of this excerpt can be read at TheDailyBeast.com.