By definition, a check is a bill of exchange drawn on a bank and payable on demand. 27. Section 185, Negotiable Instruments Law. It is a written order on a bank, purporting to be drawn against a deposit of funds for the payment of all events, of a sum of money to a certain person therein named or to his order or to cash, and payable on demand. 28 Black's Law Dictionary (5th Ed.) p. 215. Unlike a promissory note, a check is not a mere undertaking to pay an amount of money. It is an order addressed to a bank and partakes of a representation that the drawer has funds on deposit against which the check is drawn, sufficient to ensure payment upon its presentation to the bank. There is therefore an element of certainty or assurance that the instrument will be paid upon presentation. For this reason, checks have become widely accepted as a medium of payment in trade and commerce. Although not legal tender, checks have come to be perceived as convenient substitutes for currency in commercial and financial transactions. The basis or foundation of such perception is confidence. If such confidence is shaken, the usefulness of checks as currency substitutes would be greatly diminished or may become nil. Any practice therefore tending to destroy that confidence should be deterred, for the proliferation of worthless checks can only create havoc in trade circles and the banking community.

Recent statistics of the Central Bank show that one-third of the entire money supply of the country, roughly totalling P32.3 billion, consists of peso demand deposits; the remaining two-thirds consists of currency in circulation. 29.        CB Review, August, 1986, p. 6. For example, for the month of August, 1986, the total money supply was P32.326 billion, of which P21.640 billion represented currency in circulation and P10,677 billion, peso demand deposits. These demand deposits in the banks constitute the funds against which, among others, commercial papers like checks, are drawn. The magnitude of the amount involved amply justifies the legitimate concern of the state in preserving the integrity of the banking system. Flooding the system with worthless checks is like pouring garbage into the bloodstream of the nation's economy.

The effects of the issuance of a worthless check transcends the private interests of the parties directly involved in the transaction and touches the interests of the community at large. The mischief it creates is not only a wrong to the payee or holder, but also an injury to the public. The harmful practice of putting valueless commercial papers in circulation, multiplied a thousandfold, can very well pollute the channels of trade and commerce, injure the banking system and eventually hurt the welfare of society and the public interest. As aptly stated — 30 Stacy, C.J., concurring in State v. Yarboro (1927) 194 N.C. 498 140 S.E. 216, 220.

"The 'check flasher' does a great deal more than contract a debt; he shakes the pillars of business; and to my mind, it is a mistaken charity of judgment to place him in the same category with the honest man who is unable to pay his debts, and for whom the constitutional inhibition against `imprisonment for debt, except in cases of fraud' was intended as a shield and not a sword."

In sum, we find the enactment of BP 22 a valid exercise of the police power and is not repugnant to the constitutional inhibition against imprisonment for debt.

This Court is not unaware of the conflicting jurisprudence obtaining in the various states of the United States on the constitutionality of the "worthless check" acts. 31.        For a survey of decisions on the subject, see Annotations, 23 A.L.R. 459 and 76 A.L.R. 1229, Constitutionality upheld: Frazier v. State (1931) 135 So. 280; Ex parte Rosencratz (1931) 299 Pac. 15; Carter v. Lowry (1929) 167 Ga. 151 S.E. 23; Caughlan v. State (1927) 22 Ala. 220, 114 So. 280; State v. Yarboro (1927) 194 N.C. 498, 140, S.E. 216; State v. Avery (1922) 207 Pac. 838, 23 A.L.R. 453; Hollis v. State (1921) 152 Ga. 192, 108 S.E. 783; McQuagge v. State (1920) 80 Fla. 768, 87 So. 60, State v. Pilling (1909) 53 Wash. 464; 132 Am. St. Contra: State v. Nelson (1931) 237 N.W. 766, 76 A.L.R. 1226; Burnham v. Com. (1929) 228 Ky. 410, 15 S.W. (2d) 256; Ward v. Com. (1929) 228 Ky 468, 15 S.W. (2d) 276; Neidlinger v. State (1916) 17 Ga. App. 811, 88 S.E. 687; Carr v. State (1895) 106 Ala. 35, 34 L.R.A. 634. It is needless to warn that foreign jurisprudence must be taken with abundant caution. A caveat to be observed is that substantial differences exist between our statute and the worthless check acts of those states where the jurisprudence have evolved. One thing to remember is that BP 22 was not lifted bodily from any existing statute. Furthermore, we have to consider that judicial decisions must be read in the context of the facts and the law involved and, in a broader sense, of the social, economic and political environment — in short, the milieu — under which they were made. We recognize the wisdom of the old saying that what is sauce for the goose may not be sauce for the gander.

As stated elsewhere, police power is a dynamic force that enables the state to meet the exigencies of changing times. There are occasions when the police power of the state may even override a constitutional guaranty. For example, there have been cases wherein we held that the constitutional provision on non-impairment of contracts must yield to the police power of the state. 32   Phil. American Life Insurance Co. v. Auditor General, 22 SCRA 135. Whether the police power may override the constitutional inhibition against imprisonment for debt is an issue we do not have to address. This bridge has not been reached, so there is no occasion to cross it.

EN BANC, Justice Yap, FLORENTINA A. LOZANO, petitioner, vs. THE HONORABLE ANTONIO M. MARTINEZ, in his capacity as Presiding Judge, Regional Trial Court, National Capital Judicial Region, Branch XX, Manila, and the HONORABLE JOSE B. FLAMINIANO, in his capacity as City Fiscal of Manila, respondents.[G.R. Nos. L-66839-42.  December 18, 1986.]