n that it is invalid, the convictions of the
five prevail over the convictions or doubts of the four, and vice versa.
Second, the Court has made exceptions to this rule in certain categories
of cases. At one time statutes interfering with freedom of contract were
presumed to be unconstitutional until proved valid,[278] and more
recently presumptions of invalidity have appeared to prevail against
statutes alleged to interfere with freedom of expression and of
religious worship, which have been said to occupy a preferred position
in the Constitution.[279]

Exclusion of Extra-Constitutional Tests

A fifth maxim of constitutional interpretation runs to the effect that
the Courts are concerned only with the constitutionality of legislation
and not with its motives, policy or wisdom, or with its concurrence with
natural justice, fundamental principles of government, or spirit of the
Constitution.[280] In various forms this maxim has been repeated to such
an extent that it has become trite and has increasingly come to be
incorporated in constitutional cases as a reason for fortifying a
finding of unconstitutionality. Through absorption of natural rights
doctrines into the text of the Constitution, the Court was enabled to
reject natural law and still to partake of its fruits, and the same is
true of the _laissez faire_ principles incorporated in judicial
decisions from about 1890 to 1937. Such protective coloration is
transparent in such cases as Lochner _v._ New York[281] and United
States _v._ Butler.[282]

Disallowance by Statutory Interpretation

A sixth principle of constitutional interpretation designed by the
courts to discourage invalidation of statutes is that if at all possible
the courts will construe the statute so as to bring it within the law of
the Constitution.[283] At times this has meant that a statute was
construed so strictly in order to avoid constitutional difficulties that
its efficacy was impaired if not lost.[284] A seventh principle closely
related to the preceding one is that in cases involving statutes,
portions of which are valid and other portions invalid, the courts will
separate the valid from the invalid and throw out only the latter unless
such portions are inextricably connected.[285] Sometimes statutes
expressly provide for the separability of provisions, but it remains for
the courts in the last resort to determine whether the provisions are
separable.[286]

_Stare Decisis_ in C