What is judicial discretion and what is its effect?

" 'Judicial discretion is that power of decision exercised to the necessary end of awarding justice based upon reason and law but for which decision there is no special governing statute or rule. Discretion implies that in the absence of positive law or fixed rule the judge is to decide a question by his view of expediency or of the demand of equity and justice.... The term implies absence of arbitrary determination, capricious disposition or whimsical thinking. It imports the exercise of discriminating judgment within the bounds of reason. Discretion in this connection means a sound judicial discretion enlightened by intelligence and learning, controlled by sound principles of law, of firm courage combined with the calmness of a cool mind, free from partiality, not swayed by sympathy or warped by prejudice or moved by any kind of influence save alone the overwhelming passion to do what is just.' " (Harris v. Superior Court, supra, 19 Cal.3d at p. 796, 140 Cal.Rptr. 318, 567 P.2d 750.)