Although there have been sharp differences of opinion among members of the Supreme Court in recent cases dealing with the tax immunity of State functions and instrumentalities, it has been stated that "all agree that not all of the former immunity is gone."[243] Twice the Court has made an effort to express its new point of view in a statement of general principles by which the right to such immunity shall be determined. However, the failure to muster a majority in concurrence with any single opinion in the more recent of these cases leaves the question very much in doubt. In Helvering _v._ Gerhardt,[244] where, without overruling Collector _v._ Day, it narrowed the immunity of salaries of State officers and federal income taxation, the Court announced "* * *, two guiding principles of limitation for holding the tax immunity of State instrumentalities to its proper function. The one, dependent upon the nature of the function being performed by the State or in its behalf, excludes from the immunity activities thought not to be essential to the preservation of State governments even though the tax be collected from the State treasury. * * * The other principle, exemplified by those cases where the tax laid upon individuals affects the State only as the burden is passed on to it by the taxpayer, forbids recognition of the immunity when the burden on the State is so speculative and uncertain that if allowed it would restrict the federal taxing power without affording any corresponding tangible protection to the State government; even though the function be thought important enough to demand immunity from a tax upon the State itself, it is not necessarily protected from a tax which well may be substantially or entirely absorbed by private persons."[245] CONFLICTING VIEWS ON THE COURT