Personal responsibility is one of the core aspects of conservatism →. The idea is relatively simple: society is the sum of a mass of individual actors, of which you are exactly one, and the better each actor takes care of their piece of society, the better society as a whole can function.
This political ideal is tempered by two realities:
Not everyone is able to handle all of their own responsibilities all of the time.
Some of society's needs cannot be wholly accounted for by summing individual responsibility.
The responses to these are straight-forward:
A part of your own responsibilities is to watch those around you, to look out for them, and to check that they're doing alright.
A part of your own responsibilities is to care about the larger state of society [1].
[1]Basically, not my monkeys, not my zoo has its limits. You live in the same zoo along with the other monkeys.
The tension that's created around personal responsibility is usually around where to split responsibilities between different parties, and where the 'personal' aspect dissolves into a larger collective responsibility.
A classic case is that of drug abuse [2].
[2]I am specifically refering here to ab-use, where the use's downsides clearly outweigh any upsides. Most drug abusers take their drugs themselves, which would appear to place stopping squarely in the sphere of their own personal responsibility.
Where it gets tricky is that their abuse is typically co-morbid with other factors and influences. They may live in an environment where it is easy to procure the drug, or difficult to avoid its presence in social situations. They may have friends or associates who enable them. In this manner the responsibility expands to encompass a larger group of individuals [2-1].
[2-1]Note that it is still clearly personal in the final analysis. Unless you are being drugged against your will, a sufficient amount of willpower can solve the problem for any given individual. That said, drugs do tend to rob their users of this kind of willpower, either directly through psychological or physiological dependence, or indirectly, through degredation of their mental faculties. See drugs → for a more detailed consideration.