We’ll take a deeper look at the quality of optimism this week, with a little help from a 19th-century neurologist, a 20th century graduate of Harvard Law School, and a set of 21st-century experiments. It’s going to be a fun week.

We’ll start by taking a new look at Martin Luther King Jr.’s famous “I Have a Dream Speech” at the March on Washington in 1963. But we won’t be focusing on his rhythmic cadence or strategic uses of pauses. Instead, we’ll turn our attention to the persuasive power he generates with his head, his arms, and even his heels. Body language, we’ll see, can be some of the most effective languages around.

The first American woman to become a Supreme Court justice. The first German Chancellor to commemorate the Warsaw Ghetto Uprising. And a brave political activist who decided the best way to make a statement would be to climb up a flagpole. We learned about each of those figures last week and are now ready to take a look at some helpful research about the quality each of them shared: they communicated with more than just their mouths.