# Is the doomsday argument flawed?

Through the doomsday argument people try to calculate the number of humans that will ever live based only on the number of humans that have lived until now. To me this arguments seems very flawed, but I might be misunderstanding it.

Let's say there is a fixed number of all members of the human species in the past and future (H). We want to estimate this number. And let's say we have a simple counter that represents the number of humans born yet (n). The counter starts from 1 with the first human. Every time the counter increases to include a new human (n+1), there is a slight chance (c) that this one human being comes up with the doomsday argument. This one human being that just came up with the DA will look at the current value of the counter (a), which represents their number in the succession of all humans. Using this number a, the human will try to estimate H, while the counter keeps counting.

I don't see how the current value a in any way depends on H in this case. It only depends on the chance c (which depends on how easy it is to come up with the doomsday argument for a human). Am I missing something?

Edit: a depends on H in that `a <= H`

• It isn't very clear to me how the possibility 'c' directly affects the counter 'n'. – William Jun 18 at 14:44
• Since humans talk to each other once one of them came up with the doomsday argument the rest can just hear about it, they need not come up with it themselves. It is unclear why the chance (c) has anything whatsoever to do with the estimates. – Conifold Jun 18 at 16:04
• c is the probability of one human coming up with the doomsday argument (and then telling everyone). If c is 0.1, it might take about 10 people until the first one comes up with the argument. If c is 0.01, it might take 100 people. The possibility does not effect the counter, but the first person to come up with the argument will look at the counter and base the estimation on the current counter value. – alexander Jun 19 at 11:16