system
Given the following post, respond as if you're commenting on Reddit:
human
Disregarding the fact that people are considered mature or an adult at age 18(in most countries). At what age do different philosophers consider a person an adult?

I'm guessing that people have different ideas of what's the ideal adult age. I think that I could consider myself an adult at age 25 and beyond. I could call myself an adult at age 18 anytime but I wouldn't feel like one.
gpt
What we mean when we say that someone is mature is that they have developed a certain set of capacities. These capacities can be a number of things, including things like the capacity to drive a car well. But the most important type of capacity we tend to associate with maturity is rational capacities. The reason that we don’t punish children as much when they commit the same crime as adults, or that we don’t let them vote, is that we feel they don’t have sufficient rational capacities to fully understand what they are doing. Rational capacities seem especially important for assigning moral responsibilities to people. The problem is that there is no clean line we can draw where before the line someone lacks rational capacities and past the line they have them. Further, it’s possible that there exists some very mature 15 year old who has developed sufficient rational capacities, and that there is also a very immature 25 year old who does not have these capacities. 

The law draws a line at a certain age because of pragmatic considerations. It is simply impossible to go case-by-case and decide whether each person is currently rational enough to take on the full moral responsibilities of an adult. So we draw a somewhat arbitrary line that we decide is good enough, but not perfect. Philosophers don’t have to draw such a line, so there’s no age that a philosopher is going to tell you that someone is an adult outside outside of the political community they’re in.