Anyone with a basic understanding of Parliamentary Sovereignty will understand how today's ruling is necessary. It is by no means a way to stop Brexit, it is to decide how it will come about. Under the doctrines of Parliamentary Supremacy, Parliament has the power to create and end any law, except one which will bind a future Parliament. Theresa May would like a "hard" Brexit and so one in which we cannot enter the EU again - this was repeated many times during the campaign and so is a hard truth of the referendum result. Therefore, creating such a legislation is binding future Parliaments as they will not be able to unmake or change the law which has been made. Therefore, this has had to go through the HOC to ensure this DOESN'T happen and because Parliament as one is supreme compared to Theresa May herself. We are a democracy, not a dictatorship. Parliament call the shots in this country, not one leader with "power".