Short answer. Yes. Under Article 272 of the Revised Penal Code, anyone who purchases, sells, kidnaps, or detains a human being for the purpose of enslaving him commits the crime of slavery. The penalty is even heavier if the purpose is to assign the victim to some immoral traffic.
What the law says
upon anyone who shall purchase, sell, kidnap or detain a human being for the purpose of enslaving him
Revised Penal Code, Article 272 — Slavery And Immoral Traffic. Read the full provision →
What the law says
If the crime be committed for the purpose of assigning the offended party to some immoral traffic, the penalty shall be imposed in its maximum period
Revised Penal Code, Article 272 — Slavery And Immoral Traffic. Read the full provision →
Slavery is a crime
Article 272 directly criminalizes slavery. It imposes its penalty upon anyone who shall purchase, sell, kidnap or detain a human being for the purpose of enslaving him. Four acts are covered — purchasing, selling, kidnapping, or detaining a person — when done with the purpose of enslavement. The buying and selling of a human being is therefore squarely a crime under the Code. The defining element is the purpose: the offender must act in order to enslave the victim, that is, to reduce the person to a condition of servitude and treat him as property rather than as a free human being.
The purpose of enslavement is the key element
What separates this crime from a simple detention is the enslaving purpose. Article 272 requires that the purchase, sale, kidnapping or detention be done for the purpose of enslaving the victim. Depriving someone of liberty for some other reason may fall under different crimes, such as illegal detention. Here, the offender's aim is to hold the person in servitude — to own or dispose of a human being. That intent is what the prosecution must establish, alongside one of the listed acts. The article recognizes that treating a person as merchandise is a wrong distinct from, and graver than, ordinary restraint.
A heavier penalty for immoral traffic
The article singles out an aggravated form. It provides that If the crime be committed for the purpose of assigning the offended party to some immoral traffic, the penalty shall be imposed in its maximum period. In other words, where the victim is enslaved so as to be devoted to some immoral traffic, the punishment is raised to the top of the range the article sets. This reflects the added evil of exploiting the enslaved person for immoral purposes. The base penalty is a term of imprisonment together with a fine, increased to its maximum in this aggravated situation.
How this fits with other laws
Article 272 answers your question under the Revised Penal Code: yes, slavery and the buying and selling of a human being are crimes. It is not the only law on point, though. Trafficking in persons is now addressed comprehensively by special legislation — principally Republic Act No. 9208, as amended by Republic Act No. 10364 — which defines trafficking broadly and carries its own, often heavier, penalties. Depending on the facts, conduct that enslaves or trades a human being may be prosecuted under those anti-trafficking laws as well as, or instead of, Article 272. The Code provision remains, but it no longer stands alone.