The Judicial Committee of the Privy Council, which now exercises
the functions formerly belonging to the Lords of Trade and
Plantations, and is in fact the same body, deals in a similar way
today with questions of a constitutional character. If one of
the provinces included in the Dominion of Canada should in its
local legislation infringe upon a field belonging to the Dominion
Parliament, this committee can "humbly advise the king" that the
act in question is for that reason void.[Footnote: In July, 1903,
for instance, an Act of the Province of Ontario, entitled the
"Lord's Day Profanation Act," was thus declared _ultra
vires_.]

The Revolution found the new-made States of the Union without
this safeguard against a statute repugnant to a higher law. They
had enjoyed as colonies the advantage which Burke declared was an
ideal in government. "The supreme authority," he said, "ought to
make its judicature, as it were, something exterior to the
State." The supreme judicature for America had been in England.
There was now no King in Council with power to set a statute
aside forthwith by an executive order. But the other function of
the King in Council, that of acting as a court of appeal from
colonial judgments, had been simply transferred to new hands.
The State into which the colony had been converted now exercised
it for itself and through her judiciary.

The judgment of a court is the legal conclusion from certain
facts. Unless it is a legal conclusion from the facts on which
it purports to rest it is erroneous, and, if there is any higher
court of appeal, can be reversed. If such a judgment depends
upon a statute which justifies or forbids the act or omission