If we take free market to be the position that the State (i.e. the political authority) should not act in the market, is this a liberal position and if not is it still coherent?
It seems that the free market differs from the liberalism in that free-market-ism (FM) does not propose that authority actually act to ensure freedom, equality, etc. FM in fact seems to argue that the State ought not to act in the market or should limit its action as much as possible.
It seems then that FM might be coherent or at least not incoherent in the way that liberalism as a political philosophy is, since FM proposes that the State actually no act and thus produces freedom and liberty. It is actually a political philosophy of markets that in taking liberty as the object of authority actually has the State not acting. It does not propose that the authority ensure liberty, but that it ensure liberty by not acting.
That all being said, every exchange or contract in the market implicitly assumes the authority of the State. All are ultimately enforced and ensured by the authority and force of the State. This implies that the State has an authority to determine what contracts to enforce. This then runs against the position of the FM for it is within the scope of the State’s authority to determine the validity of certain contracts.
The Roman Empire enforced contracts of slavery whereas the US generally does not (excluding usurious contracts). Certain Catholic princes of yesteryear did not enforce usurious contracts, whereas the US does. Each may have reasons for or against enforcing such contracts, but the point is that the State determines which contracts to enforce which provides the ultimate ground for the market to function in the first place.
It seems then that FM may be a cousin to Liberalism, but it does not seem to be a part of Liberalism or necessarily liberal in itself with respect to its commitments to authoritative action. However, it does have the same temperament of contempt for authority and the illusion that it can be overcome or removed.
*This all under the presumption of my definition of FM.