We are still posting orders over the festive period (in line with Royal Mail posting dates), however we are unable to guarantee that any orders placed from the 19th December will arrive in time for Christmas. Orders for collection are also still being processed, but we cannot guarantee arrival before Christmas. For more information, visit our Shipping page here. Dismiss
![On the Principles of Social Gravity [Revised Edition] cover](https://cdn.theportobellobookshop.com/img/9781622733347.jpg?p=search)