Flatten the chicken breasts by cutting them in half, putting between 2 layers of plastic wrap, and then pounding with a mallet or rolling pin until 1/4 inch thick. Season with salt and pepper.
Add olive oil to a large skillet, place over high heat, then add as many of the chicken breast slices as will fit without overlapping. Brown for 2 minutes on each side, then set aside in a warm oven.
To make the sauce, reheat the skillet over medium heat. Add the wine and deglaze, reducing for about 2 minutes while constantly scraping the browned bits of the bottom of the pan. Stir in capers and lemon juice, then remove from heat and add the butter.
Stir until melted.
Pour the sauce over the chicken and serve.