In the UK there has traditionally been a considerable degree of overlap in terms of personnel and functions between the different branches of the state. Academic writers including Bagehot (The English Constitution 1867) identify this as being a result of the British constitution being a parliamentary, as opposed to a presidential, system. In a parliamentary system, the legislature selects the political part of the executive branch, which then is then ultimately dependent on the legislature for its position and power. For this reason, parliamentary systems are often seen to create a fusion of powers rather than a separation of powers.