FACTS: 
1. Spouses  del Rosario (herein respondents), jointly and severally executed, signed and delivered in favor of Radiowealth Finance Company a Promissory Note  for P138,948. 
 
2. Thereafter, respondents defaulted on the monthly installments. Despite repeated demands, they failed to pay their obligations under their Promissory Note.
 
3. Petitioner claims that respondents are liable for the whole amount of their debt and the interest thereon, after they defaulted on the monthly installments.
 
4. Respondents, on the other hand, counter that the installments were not yet due and demandable. Petitioner had allegedly allowed them to apply their promotion services for its financing business as payment of the Promissory Note. This was supposedly evidenced by the blank space left for the date on which the installments should have commenced. 

• In other words, respondents theorize that the action for immediate enforcement of their obligation is premature because its fulfillment is dependent on the sole will of the debtor. Hence, they consider that the proper court should first fix a period for payment, pursuant to Articles 1180 and 1197 of the Civil Code. This contention is untenable.

 
ISSUE: 
1. W/N leaving the date/period blank for the monthly installments cancels out the obligation to pay in obligations with a period
 
2. W/N the obligation has become due and demandable despite the period to pay the obligation left blank
 
RULING: 
1. NO, If this was the intention of the parties, they should have so indicated in the Promissory Note. However, it did not reflect any such intention. 

• On the contrary, the Note expressly stipulated that the debt should be amortized monthly in installments of P11,579 for twelve consecutive months. While the specific date on which each installment would be due was left blank, the Note clearly provided that each installment should be payable each month.
• Furthermore, it also provided for an acceleration clause and a late payment penalty, both of which showed the intention of the parties that the installments should be paid at a definite date. Had they intended that the debtors could pay as and when they could, there would have been no need for these two clauses.

 
2. YES, SC said, onvincingly, petitioner has established not only a cause of action against the respondents, but also a due and demandable obligation. 

• The obligation of the respondents had matured and they clearly defaulted when their checks bounced. Per the acceleration clause, the whole debt became due one month (April 2, 1991) after the date of the Note because the check representing their first installment bounced. 

 WHEREFORE, the Petition is GRANTED. 

• The appealed Decision is MODIFIED in that the remand is SET ASIDE  and respondents are ordered TO PAY P138,948, plus 2.5 percent penalty charge per month beginning April 2, 1991 until fully paid,  and 10 percent of the amount due as attorneys fees. 

Under the Revised Penal Code Article 12-
The following are exempt f r om criminal liability:

1. An imbecile or an i n s a n e person, u n l e s s the l a t t er has a c t e d during a l u c id interval.

When the imbecile or an insane person has committed an act w h i c h the l aw defines as a felony (delito), the court shall order h i s confinement i n o n e o f t h e h o s p i t a l s or asylums e s t a b l i s h e d for
p e r s o n s thus afflicted, w h i c h he shall not be permitted t o l e a v e without first o b t a i n i n g t h e permission of the same court.

2. A p e r s o n under n i n e years of age.* (now 15 years of age and under)

3. A p e r s o n over n i n e y e a r s of a g e and under fifteen, unless he has a c t e d w i t h discernment, i n
w h i c h case, s u ch minor shall be p r o c e e d e d against i n accordance w i t h the provisions of Article 80 of t h i s Code. (now over 15 years of age and under 18)

4. Any p e r s o n who, w h i l e performing a lawful act with due care, c a u s e s a n injury by m e r e 
a c c i d e n t w i t h o u t fault or i n t e n t i o n of c a u s i n g it.

5. Any p e r s o n who acts under the compulsion of an i r r e s i s t i b l e force.

6. Any p e r s o n w h o a c t s u n d e r t h e impulse o f a n  uncontrollable fear of a n equal or g r e a t e r injury.

7. Any p e r s o n w h o fails t o perform an act required by law, w h e n p r e v e n t e d by some lawful or insuperable cause.

*A child fifteen years of age or under is exempt from criminal liability under Rep. Act No. 9344 (Juvenile Justice and Welfare Act of 2006). When s u c h minor i s adjudged t o b e criminally irresponsible, t h e court, in conformity w i t h t h e provisions o f t h i s a n d the preceding paragraph, shall commit  him t o         t h e care and custody of h i s family w h o shall be charged w i t h h i s surveillance and education;
o t h e r w i s e , he shall be committed t o the care of some i n s t i t u t i o n or p e r s o n m e n t i o n e d
i n s a i d Article 80.**

Source: The Revised Penal Code of the Republic of the Philippines/Juvenile Justice and Welfare Act of 2006.

Article 11. Justifying circumstances. — The following do not incur any criminal liability:

1. Anyone w h o a c t s i n d e f e n s e of h i s p e r s o n or rights,provided that t h e f o l l o w i n g c i r c u m s t a n c e s concur:

First. Unlawful aggression;
Second. Reasonable n e c e s s i t y of t h e means employed to prevent or repel it;
Third. Lack of sufficient provocation on the part of the person defending himself.

2. Anyone who acts in defense of t h e person or rights of his spouse, ascendants, descendants, or legitimate, natural, or adopted brothers or sisters, or of h i s relatives by affinity in the
same degrees, and those by consanguinity w i t h in the fourth civil degree, provided that t h e f i r s t a n d second requisites prescribed in t h e next preceding circumstance are present, and the further requisite, in case the provocation was given by the person attacked, that the one making defense had no part therein.

3. Anyone who acts in defense of t h e person or rights of a stranger, provided that the first and second requisites mentioned in t h e first circumstance of t h i s article are present and that the person defending be not induced by revenge,
resentment or other evil motive.

4. Any p e r s o n who, in order t o a v o i d an evil or injury, does an act w h i c h c a u s e s damage t o another, provided that the following r e q u i s i t e s are present:

First. That t h e evil sought to be avoided actually exists;
Second. That t h e injury f e a r e d be greater t h a n that done to avoid it.
Third. That t h e r e be no o t h e r practical and l e s s harmful means of p r e v e n t i n g it.

5. Any p e r s o n w h o a c t s in t h e fulfillment of a duty orin t h e lawful e x e r c i s e of a right or office.

6. Any p e r s o n w h o a c t s i n o b e d i e n c e t o a n order i s s u edby a superior for some lawful purpose.

Source : The Revised Penal Code

​Mala in se and mala prohibita, distinguished.

There is a distinction between crimes which are mala in se, or wrongful from their nature, such as theft, rape, homicide, etc., and those that are mala prohibita, or wrong merely because prohibited by statute, such as illegal possession of firearms.

​Crimes mala in se are those so serious in their effects on society as to call for almost unanimous condemnation of its members; while crimes mala prohibita are violations of mere rules of convenience
designed to secure a more orderly regulation of the affairs of society.

​(Bouvier's Law Dictionary, Rawle's 3rd Revision)