Preheat the oven to 425°F.  

Sift the flour, baking powder, salt, and baking soda into a large mixing bowl. Add the butter and work it in with your fingers or a fork until the mixture resembles coarse crumbs.

Stir in the buttermilk just until the dough comes together, being very careful not to overwork the dough.   Lightly dust a work surface with flour.

Turn the dough out onto the work surface and pat into a 1/2-inch-thick round. Cut out the biscuits with a 2-inch cookie cutter, re-rolling the scraps.

Place the biscuits about 1 inch apart on an ungreased baking sheet.   Bake until golden on top and lightly brown on the bottom, about 12 minutes.   Serve warm with butter.