as discretionary. It confers a discretion to release, or not to release,
the taxpayer according to the board's opinion of the justice of the
case. Except for implications or inferences from the three para-
graphs prescribing the conditions precedent, the sub-section gives
no information as to the considerations by which an exercise of the
discretion is to be guided. The nature of those considerations
must be gathered from the scope and object of the provision. No
doubt in a case coming within one of the prescribed conditions the
board cannot proceed to grant or withhold relief on grounds which
are irrelevant to the incidence and consequences of the tax and the
effect of its exaction upon the affairs of the taxpayer. It would, for
example, be outside the ambit of their discretion to withhold relief
in order to force the taxpayer to conform with some quite unconnected
administrative policy adopted by another department of government.
Expressions to be found in Ex parte Falkiner (1) cannot be pressed
too far. When Isaacs J. says that the only right of the taxpayer is
to have a chance of getting the discretion of the board exercised in
his favour, he should not be understood as meaning that the taxpayer
has no right to insist that the board shall make a discretionary
determination of his application and that it shall act on grounds
only which fall within the scope and purpose of the provision. The
right may not be very valuable. For, in the first place, the members
of the board are not obliged to state their reasons and they may
make it well nigh impossible for him to discover why they refused
his application. In the second place, where no limits are expressly
imposed by the legislature on an administrative discretion, the
questions what are, and what are not, legitimate considerations for
its exercise must always be disputable and open to wide differences
of opinion. But, nevertheless, in theory a legal right exists to
compel an exercise of the discretion on grounds which are not
extraneous and irrelevant to its purpose. I do not think that
par. a, b or c of sub-sec. 1 or sub-sec. 3 contains anything