History is, or should be, about the past. Two of the more common historical howlers involve projecting contemporary values and habits on to the deceased and theorising about positions the dead might have taken if only they were alive.

The most recent victim of bad history is the Liberal Party ­founder Robert Menzies (1894-1978). Writing in The ­Saturday Paper last weekend, ­Sophie Morris declared: “This week there was muttering among certain Liberals that Robert ­Menzies would be turning in his grave at the spectacle of the party he founded on the bedrock of ­individual freedom rejecting a conscience vote on same-sex marriage.”

The assertion that Menzies, who died almost four decades ago, would have advocated a conscience vote on same-sex marriage for Liberal Party parliamentarians is ahistorical. No one knows what position Menzies would have taken on this issue — either for or against.

Victorian Liberal Party leader Matthew Guy ran a similar line across a broader canvas. Guy said: “People who feel that (Liberal Party) members should be bound on matters of conscience by a party vote … need to go back and look at the rationale on which our party was founded by Robert Menzies; it wasn’t one of binding votes, it was one of conscience.”

Menzies essentially founded the Liberal Party in late 1944 and it came into operation the following year. In December 1949, he led the Liberal Party-National Party Coalition to government. Menzies remained prime minister until his retirement in January 1966.

It is true that Liberal Party MPs were given a conscience vote on all pieces of legislation — unlike the Labor Party, which insisted from the time of its formation that parliamentarians pledge themselves to follow the line determined in caucus.

This has remained the fact under all subsequent Liberal prime ministers — Harold Holt, John Gorton, William McMahon, Malcolm Fraser, John Howard and Tony Abbott.

Yes, including Abbott. Any Liberals in the House of Representatives or the Senate who support a private member’s bill legalising same-sex marriage will not lose party membership and will not be excluded from the Liberal partyroom. In other words, they enjoy the benefits of a conscience vote on all legislative matters — ministers, parliamentarians and backbenchers alike.

The Prime Minister has stated that all members of the executive — that is, ministers and parliamentary secretaries — are required to abide by decisions of the cabinet and/or the partyroom or resign from the frontbench. This is consistent with the tradition established by Menzies.

Leslie Bury (1913-86) was appointed to the Menzies ministry in late 1961 as minister for air and minister assisting the treasurer. Bury, the member for Wentworth in Sydney (Malcolm Turnbull’s seat today), was a believer in free trade and a fan of political philosopher Adam Smith.

In July 1962, Bury contradicted Coalition policy by arguing that Britain’s entry into the European Economic Community would not have a deleterious impact on the Australian economy. At the time, the Menzies government was negotiating with Britain concerning the impact of its decisions with respect to the EEC on the Australian rural industry.

Menzies sacked Bury on account of the fact, as a junior minister, he had made statements contrary to government policy. Bury was not reappointed to the ministry for more than two years. Clearly the assertion that Menzies allowed conscience, or free, votes to his ministers is junk. Absolute junk, by commentators who should know better.

In October 2005, the Commonwealth Parliamentary Library published a research note titled Crossing the floor in Federal ­Parliament: 1950-August 2004. It revealed that during Menzies’ prime ­ministership, 5 per cent of the government’s legislation saw government members cross the floor. The busiest floor-crossers were Liberal senators Reg Wright (Tasmania) and Ian Wood (Queensland). Neither served in a ministry led by Menzies.

Then there is the myth that Menzies was some kind of small-l liberal who supported what would now be called “progressive” ­causes. It is not what was said about Menzies during his prime ministerships — heading the United Australia Party government between April 1939 and August 1941 and the Coalition government ­between December 1949 and January 1966.

It is true that, in his 1967 book Afternoon Light, Menzies wrote: “We took the name ‘Liberal’ because we were determined to be a progressive party, willing to make experiments, in no sense reactionary but believing in the individual, his rights and his enterprise, and rejecting the socialist panacea.”

But it is also true that Menzies banned the Communist Party of Australia in June 1940 (at the time of the Nazi-Soviet Pact) and attempted unsuccessfully to ban the CPA in 1951 (at the time of the ­Korean War).

Menzies committed what is now called the Australian Defence Force to war in September 1939 and, against the wishes of the Labor opposition, dispatched the Second Australian Imperial Force to engage Nazi Germany and its allies on the battlefield. Menzies also committed the ADF to the following conflicts: Korea, the Malayan Emergency, Confrontation (with Indonesia over Malaysia) and Vietnam. Menzies was the first Australian prime minister to conscript young men for military service overseas.

The Menzies government also supported the activities of ASIO during the Cold War. Moreover, in 1960 it widened the powers of the Crimes Act. As Don Watson documents in his book Brian Fitzpatrick: A Radical Life, the ACTU described this legislation as “typical of a police state”.

Some left-of-centre commentators are using their born-again attitude to Menzies as a means of criticising Abbott. For example, Judith Brett told The Saturday Paper that Abbott is “probably the most conservative prime minister we have ever seen”. Yet, in her 1992 book Robert Menzies’ Forgotten People, Brett wrote that Menzies’ anti-communist rhetoric could be traced to “the anal erotic imagery of the attack from behind”. Really.

The fact is that we have no idea how Menzies would handle such contemporary issues as same-sex marriage. And we do not have a clue about how Abbott would have tackled the foreign policy and ­national security challenges with which Menzies had to deal.