"x x x.
There is fraud when, through the insidious words or machinations of one of the contracting parties, the other is induced to enter into a contract which, without them, he would not have agreed to.[29] There is undue influence when a person takes improper advantage of his power over the will of another, depriving the latter of a reasonable freedom of choice. The following circumstances shall be considered: the confidential, family, spiritual and other relations between the parties, or the fact that the person alleged to have been unduly influenced was suffering from mental weakness, or was ignorant or in financial distress.[30]
Ei incumbit probatio qui dicit, non qui negat. He who asserts, not he who denies, must prove. We have consistently applied the ancient rule that if the plaintiff, upon whom rests the burden of proving his cause of action, fails to show in a satisfactory manner facts on which he bases his claim, the defendant is under no obligation to prove his exception or defense.[31] In the instant case, the self-serving testimony of the petitioners are vague on what acts of Leopoldo Sevilla constituted fraud and undue influence and on how these acts vitiated the consent of Felisa Almirol. Fraud and undue influence that vitiated a party’s consent must be established by full, clear and convincing evidence, otherwise, the latter’s presumed consent to the contract prevails.[32] Neither does the fact that the donation preceded the partition constitute fraud. It is not necessary that partition should first be had because what was donated to Leopoldo was the 1/2 undivided share of Felisa in Lot No. 653.
Moreover, petitioners failed to show proof why Felisa should be held incapable of exercising sufficient judgment in ceding her share to respondent Leopoldo.[33] As testified by the notary public who notarized the Deed of Donation, Felisa confirmed to him her intention to donate her share in Lot No. 653 to Leopoldo. He stressed that though the donor was old, she was of sound mind and could talk sensibly. Significantly, there is nothing in the record that discloses even an attempt by petitioners to rebut said declaration of the notary public.
x x x."