Plaintiffs Benita O. Chioco  and her husband Constancio Padilla are appealing  the orders of the Court  of First Instance of Nueva Ecija of June  11,  1956, dismissing their complaint, and of July 27, 1956, denying their motion for reconsideration, in Civil Case No. 2090.

From  what we gather from the pleadings  and the appealed orders, the  following facts may be narrated.  On February 5, 1927, Lot 1709 of the San Jose Cadastre, Nueva Ecija,  with an area of 1,606 square meters, was registered under  the  Torrens  System in the name of Liceria de la Cruz and Lucina  Virgo  (OCT 6964). Some time in 1929, Julia Ortiz Luis,  mother of  plaintiff Chioco,  allegedly bought from the registered  owner Liceria de  la  Cruz, grandmother of the defendant, Severo Ongsiapco,  a portion of Lot 1709,  with an area of  about 444 square meters, but the deed of sale was never  registered, neither could the original or a copy of the instrument be  produced.

On March 7, 1931, the entire Lot 1709 was sold  at public auction by virtue of a decision in favor of Benedicto Adorable and  against  Liceria de la Cruz, Adorable in  due time being issued TCT 14106, after  the expiration of the period for redemption.   On December 22, 1938,  plaintiff Padilla allegedly  bought a portion of Lot 1709,  with an area of  750 square meters, and on April 24,  1939, at Padilla's request, he was issued a co-owner's  copy of Adorable's  title, TCT 14106.

On December 19, 1940, the heirs of Adorable sold to Flora Ramos the  remaining portion  of Lot 1709,  with an area of 856 square meters.   (Entry No.  2847/T-14106, p. 55, Record on Appeal).  On September 20, 1945, Flora Ramos transferred  her  rights to  Tomas  Rizo.   (Entry No. 2048/T-14106, p, 55, Record on Appeal).  On October 4, 1945, Padilla sold the  portion of Lot  1709 that he bought  from  Adorable to  defendant Severo Ongsiapco, thereby making the latter and Tomas Rizo co-owners of the whole Lot  1709.   (Entry No. 2051/T-14106, pp. 54-55, Record on Appeal).   On March 29, 1946, Tomas Rizo sold his portion of the Lot 1709 to Ongsiapco and his wife and co-defendant,  Irene  Macaso,  thereby consolidating their ownership of  the  whole lot, and  on April 8, 1946, said spouses were issued TCT No. 22226.   (Entry No. 2708/T22226, p. 56,  Record on Appeal.)

According to the plaintiffs, however, sometime in the year 1946, the heirs of Adorable,  buyer at  public auction of Lot 1709, gave the option to repurchase the said lot to defendant Ongsiapco as an heir  (grandson of Liceria de la Cruz)  "and that is how it came to  be that said defendants became the registered owners  of Lot  1709, inadvertently  including  1709-A"  (the  portion allegedly bought  by Julia Ortiz  Luis,  mother of plaintiff  Chioco, way back in  1929).  (Paragraph 7, Complaint).  Based on this theory, plaintiffs-appellants filed the  present case, with two causes of action, praying  among other  things that judgment be rendered in their favor, ordering defendants to segregate from their title the portion of Lot  1709 allegedly bought by  Julia Ortiz Luis, and  to execute the necessary conveyance thereof to them.

On May 7, 1956, defendant Irene Macaso  filed a motion to dismiss the complaint on the grounds of lack  of cause of action and prescription.  On the same date, her husband and co-defendant, Ongsiapco, filed  his answer with special defense of lack of cause of action,  prescription, and estoppel, and with  counterclaim  for damages and attorney's fees.  On June  11, 1956, after plaintiffs had filed their "Reply and Answer to Counterclaim" and "Answer to the Motion to Dismiss", the trial court  dismissed the complaint against  both defendants.  Acting  upon a motion  for reconsideration,  the trial  court on July 27,  1956,  modified its previous order of dismissal "in the sense that the order of dismissal with respect to defendant Irene Macaso refers to both causes  of  action,  but with respect  to  the first defendant, Severo B.  Ongsiapco,  it refers  merely to the first cause of action."

On appeal, appellants claim that:

"I. The lower court erred in dismissing the first cause of action of the  complaint with respect  to both defendants.

"II. The lower court erred in holding  that because the land is registered the plaintiff's have constructive knowledge  of such registration, and more than ten years having elapsed,  'prescription bars the  action for  any reason,' in the  language of the  court."

Appellants contend  that  since  Ongsiapco,  did not file a motion to  dismiss  the first  cause  of  action,  the  trial court erred in dismissing the complaint on  said first cause of action.  However,  in his answer, Ongsiapco interposed two  special  defenses,  namely,  that  the cause  of action states  no cause of action,  and that the cause of action, if any, is  barred by prescription.   The question may  be asked  as to whether a complaint may be dismissed when no motion for  dismissal is filed, but  one or more of the grounds of dismissal  as provided in  the  Rules  of Court is pleaded as an affirmative defense.  Section 5,  Rule 8 of the  Rules  of Court, reads  as follows:

"Sec. 5. Affirmative defenses. If  no  motion to dismiss has been filed, any of the grounds  therefor as provided in  this rule, may be pleaded  as an affirmative defense and  a  preliminary hearing may be had thereon  as if a motion to  dismiss has been filed."

We believe and hold that an affirmative defense contained in an  answer, such as, prescription, may be  regarded as having the effect of a motion to dismiss, as may be gathered from Section 5  of  Rule 8  of the Rules of Court, above-reproduced :

"The provision of section 5  permits a party  in  effect  to answer and demur in  the same pleading, for the motion  to dismiss of the Rules of Court  takes the place of the demurrer of the former Code of Civil  Procedure. * *  *" (Francisco, Rules of Court, Vol.  I, 1948  Ed., p. 275).

"Under this section (Sec. 5, Rule 8), any defense that may be raised by a motion to dismiss under section I, may also be interposed by answer with equal validity and effect as if  a motion to dismiss had been filed."  (MEJIA Civil Practice and  Procedure, Vol. I, p. 282, citing Salvador vs. Locsin, 931  Phil., 225 words in parenthesis supplied).

"When any of the  grounds mentioned in section 1 is alleged as an  affirmative defense in the answer, the  court may  hold a preliminary hearing on such special defense as if a motion to dismiss on  that ground had been filed."   (IBID., pp.  282-283, citing Maglunob vs. Nafco, 94 Phil., 461; 50 Off. Gaz. [3], 1081).

The main  ground  of the dismissal of the  complaint was prescription;  that  since the present  action was  brought in  1956, about twenty-seven years after the alleged purchase of the portion of Lot 1709 in question by plaintiffs' predecessor-in-interest, or seventeen years from  1939 when appellants  claim  to have known that Lot 1709  was registered  land, the action  is barred.   Appellants  assail this ruling, claiming that  there is no prescription in this case because: (1)  defendant Ongsiapco is  a privy  of Liceria de  la  Cruz, and the sale executed  by the latter, although not  registered, is  perfectly  valid  and binding not  only upon the contracting parties  but also upon their privies (supposedly including  herein  defendant-appellee Ongsiapco) ;  (2) prescription neither applies to a subsisting and continuing trust  nor  to an  action by the vendee  of real property in possession  thereof  to  obtain the conveyance of it;  and  (3)  defendants-appellees are purchasers in bad faith.   Was privity really involved here?  In other words, may defendant Ongsiapco be  regarded as a privy of his grandmother, Liceria de la Cruz, as regards the parcel in question?   True,  Ongsiapco  is  the grandson  of  Liceria de la Cruz.  However, the basis of privity is not personal relationship but rather property:

"The  ground  of  privity  is property,  not  personal  relation." (Bailey vs. Sundberg,  49  F. 583,  586 1  CCA. 387)  (WORDS & PHRASES, Vol. 33, p. 799)

"'Privies' occupy  that  relation to  others because of derivating rights of property; 'privity' relating  to persons in  their relation to property, not to any question independent of property."  (Ladonia State Bank vs. McDonald (Tex.) 7 S.W. 161, 162.  IBID., p.  799)

"The  ground  of  'privity'  is  property,  not  personal  relation. Absolute identity of interest is essential to 'privity.' * * *."  (Logan vs. Atlanta & C.A.L.R.  Co.,  64 S.E. 515, 516, 82 S.C. 518, quoting Bigelow, Estop, p. 142; Freem.  Judgm.  Sec. 162; Smith vs. Moore 7 S.C. 215, 24  Am.  Rep. 479.)   (IBID., p. 800).

From the facts above-narrated, it is clear that the defendants herein  derived  their title to  Lot 1709, particularly, the portion thereof in question, not because of their relationship with the original owner, Liceria de la Cruz, but by virtue of a series  of transactions and conveyance beginning with  the public auction sale  of  the whole Lot 1709 in favor of Adorable  and the subsequent sales by Adorable's heirs of the said lot  to different buyers, including plaintiff Padilla, culminating in  the conveyance  and transfer of the whole lot to. the  defendants, all of which conveyances were duly registered according to the Land Registration Act.  It cannot be true that defendant  Ongsiapco as an heir of Liceria, bought the lot, including the parcel in question directly from the heirs of Adorable in the year 1946 on an option to  repurchase, because Lot 1709 was sold at public auction in  1931 and the period of repurchase or redemption expired  in  1932.  This, aside from the  fact that,  as already stated, the  defendants bought  the whole Lot  1709 not  from  Adorable  or his  heirs but from the successive vendees of Adorable.  Neither can the claim of appellants  that the  purchase of the  land  in question by defendants  was impressed with a trust,  be accepted for the reason that, as already  said, plaintiffs' predecessor-in-interest Liceria de la Cruz  lost her  title  to the land by reason  of the auction  sale  ordered  by  the  Court.  If Adorable, the purchaser in said public  auction, could not be considered  as holding said  land in  trust, neither could his  successors-in-interest, including defendants herein, be so regarded.  And the fact that one of the plaintiffs herein,  Constancio  Padilla,  intervened  in  said purchase from Adorable, later selling the land he bought  to  the defendants  herein,  does not  strengthen nor  support the position of the plaintiffs.

In view of  the  foregoing, the orders  appealed  from are hereby affirmed, without prejudice to the continuation of the trial of the case with respect to the second cause of action  as against defendant-appellee  Ongsiapco.  Appellants will pay  the costs.

Paras, C. J., Padilla, Reyes, A., Bautista Angelo,  Concepcion, and  Endencia, JJ., concur.