1.Retributive Theory:
Based on the principle of "Tit for tat" or "An eye for an eye". i.e similar amount of pain inflict to offender as agrieved party endured.
It is a harsher theory, now mostly disregarded on humanitarian grounds, though every punishment remains retributive to an extent to restore peace and harmony.
2.Deterrent Theory: Aims to incapacitate or deter someone from committing a crime. Deter someone from committing crime
Jeremy Bentham punishment should be swift, severe, and certain.
Severity: Punishment to offender to restrict and rehabilitate but should be proportionate
Certainty: If wrong happens wrongdoer must be punished
Swift: promptness in implementation depends on nature of crime
3.Reformative Theory: The primary focus is on the reformation of the offender into a law-abiding citizen to reduce the crime in society. Remission and parole are parts of this theory.
M.K. Gandhi father of reformative stated: "Condemn the sin, not the sinner".
Vijay Kumar vs St. of UP: Clarified that punishment requires consideration of the doctrine of proportionality.
"Every saint has a past and every sinner has a future "
4.Preventive Theory: Based on the principle that "prevention is better than cure".
Repeat offenders are prevented from re-offending via death or life imprisonment.
Kailash Ramchandra vs St. of RJ: Keeping vigilance and opening a history sheet is a form of preventive punishment.