Now, these powers are undeniably large—larger, indeed, than is usually the case even in Federal systems where the unenumerated or “residuary” powers are left to the State. It is conceivable that they might be exercised to the prejudice of the Imperial Government and of the union of the two kingdoms, and there is nothing in these clauses of the Act to prevent them being so exercised. Treating it as a statute on the ordinary principles of the interpretation of statutes, the Judicial Committee would have no option but to regard as valid any legislation of the Irish Parliament that did not come within the exempted powers. With policy they are not and would not be concerned. But then it must be remembered that there is the possibility of the exercise of the veto of the Imperial Government in cases where legislation, though _intra vires_, is inequitable, inexpedient, or contrary to Imperial interests. This executive veto is really a juristic fact of great importance—it has always been present to their lordships’(24) mind as a reason for refusing to apply to the interpretation of the Federal constitutions of Canada and Australia the restrictive principles of the Supreme Court, as laid down in Marshall’s famous doctrine of “implied restraints.”(25) When no such veto is in the hands of the Central Government, it becomes necessary to restrict, either in the text of the constitution, or in judicial interpretation of it, with considerable precision, the powers of the local legislatures. This is why a true Federal system always involves a very large amount of litigation. But litigation is a thing to be avoided, if possible. It encourages political parties to carry test cases into the courts.
The problem of protecting the rights and privileges of minorities in Ireland by constitutional restrictions is the most delicate that ever perplexed the mind of the jurist. It is one which puts the Irish problem in a category by itself. In no other Constitution in the Empire—with the exception of a single clause in the British North America Act—is any attempt made to fetter the discretion of Parliaments by the imposition of juristic limitations upon their legislative capacity. To say a Parliament shall not legislate except upon certain subjects is one thing, to attempt to define _how_ it shall legislate upon those very subjects is quite another. The latter is as difficult as the former is simple. To adopt a pedestrian illustration, it is easy enough to forbid motorists to drive along certain roads, but to forbid them to drive “recklessly” along any road is another matter. “Recklessly” at once raises questions of standards of negligence and actionable rights. How are we going to distinguish “just” from “unjust” legislation, taxes which discriminate from taxes which do not, “rights” of the subject which a Parliament may disregard from those which it must respect? There has never been any doubt that a colonial legislature may deal with the common law rights of the subject as it pleases, may abolish trial by jury, suspend the writ of _habeas corpus_, pass bills of attainder, enact _ex post facto_ legislation, take private property without compensation, and indemnify the Executive against actions for breaches of the law—if any doubt ever existed it was set at rest by the Colonial Laws Validity Act. But in the case of Ireland it was thought necessary—owing, doubtless, largely to the fears excited in the minds of Englishmen by the Protestant minority in Ulster and the commercial interests in both countries—to insert in the earlier Home Rule Bills an elaborate series of restrictions upon the exercise of even those legislative powers which the Irish Parliament might admittedly possess. For a parallel to these restrictions one would have to go back to the Constitution of the United States and the philosophy of “natural rights.” A more difficult problem it is impossible to conceive, because a Constitution of this kind runs counter to the whole tradition of Parliamentary sovereignty in this country and the colonies. Anyone who takes the trouble to study the decisions of the Privy Council when colonial legislation has been impugned on the ground of its infringing the common law rights of the subject or “natural justice”(27) will discover that constitutional limitations of this kind upon the powers of colonial Legislatures are not recognised by our judges. In the absence of express words in the colonial Constitutions, such restraints do not exist. “The only thing,” as Lord Halsbury grimly remarked on one occasion, for the subject whose actionable rights are taken away by a Colonial Act of Indemnity “to do is to submit.”