While the discretion to change the policy in exercise of the executive power, when not trammeled by any statute or rule is wide enough, what is imperative and implicit in terms of Article 14 is that a change in policy must be made fairly and should not give the impression that it was so done arbitrarily or by any ulterior criteria. The wide sweep of Article 14 and the requirement of every State action qualifying for its validity on this touchstone irrespective of the field of activity of the State is an accepted tenet. The basic requirement of Article 14 is fairness in action by the State, and no arbitrariness in essence and substance is the heartbeat of fair play. Actions are amenable, in the panorama of judicial review only to the extent that the State must act validly for a discernible reason, not whimsically for any ulterior purpose. The meaning and true import and concept of arbitrariness is more easily visualized than precisely defined. A question whether the impugned action is arbitrary or not is to be ultimately answered on the facts and circumstances of a given case. A basic and obvious test to apply in such cases is to see whether there is any discernible principle emerging from the impugned action and if so, does it really satisfy the test of reasonableness. Where a particular mode is prescribed for doing an act and there is no impediment in adopting the procedure, the deviation to act in a different manner which does not disclose any discernible principle which is reasonable itself shall be labeled as arbitrary. Every State action must be informed by reason and it follows that an act uninformed by reason is per se arbitrary The power of judicial review over a policy decision in the field of revenue is quite settled. Such a decision is not required to be tested by a Court of law with suspicious and microscopic eye. The parameters for decision are good faith and intention. A Constitutional Court will have to look at the decision made by the Executive or a Legislature.