1. Theory of Comity – foreign law is applied because of its convenience & because we want to give protection to our citizens, residents, & transients in our land
2. Theory of Vested Rights – we seek to enforce not foreign law itself but the rights that have been vested under such foreign law; an act done in another state may give rise to the existence of a right if the laws of that state crated such right.
3. Theory of Local Law- adherents of this school of thought believe that we apply foreign law not because it is foreign, but because our laws, by applying similar rules, require us to do so; hence, it is as if the foreign law has become part & parcel of our local law
4. Theory of Harmony of Laws – theorists here insist that in many cases we have to apply the foreign laws so that wherever a case is decided, that is, irrespective of the forum, the solution should be approximately the same; thus, identical or similar solutions anywhere & everywhere. When the goal is realized, there will be “harmony of laws”
5. Theory of Justice – the purpose of all laws, including Conflict of Laws, is the dispensing of justice; if this can be attained in may cases applying the proper foreign law, we must do so