A person without any tools isn't powerless, but they are pretty severely outclassed when it comes to dealing with predators that are of even vaguely the same size.* A person with a pointy stick or a rock is better off, one with access to sculpted metal (either with a pointy end, or strapped to themselves) is at a massive advantage. Once you start building even simple objects you suddenly have the ability to launch big lumps of stuff at people****.
Eventually you reach the point where a single person can press a button and launch enough nuclear missiles to wipe out all life on the planet*****. Which is pretty impressive for a pinky.
Now, that last one requires a lot of other people to keep the infrastructure in working order and make sure that the button****** is correctly wired up. So the question is, do you eventually reach the point where the increase in leverage means that a single individual can threaten all of human life without needing the massive support behind them?
And the answer looks likely to be "yes" pretty soon. The US has asked for certain details of research into weaponising bird flu to be censored. Because leading on from there it's only a few steps to something which would produce a massive epidemic. Right now, that would require a pretty large lab, but ten years from now it's likely that (a)our understanding will be much better and (b)the equipment will be a lot cheaper.
All of which makes me incredibly grateful for the work going on in antivirals. I hope that we never need them to deal with man-made threats, and that the cure wins the weapons race. I really do.
*Frankly, I wouldn't want to take on a badger with my bare hands, and they're about 20% of my mass. An adult chimpanzee weighs around the same as me, and would easily rip me into little meaty chunks. Put me up against a tiger or a bear and I'm just fucked.**
**I'm not sure if my chances of survival against a chimpanzee are any higher than against a tiger. I'd assume a tiger would slaughter a chimpanzee, but I suspect my survival rate against either would be zero.
***Editor-types, should the footnote for trebuchets be above the one for chances of survival, or beneath it? I swithered a lot, but felt this way around was clearer. I have a hunch that the correct answer is "Footnotes on footnotes are an abomination."
****Trebuchets are awesome. Ballistas too. I love the attack on Minas Tirith.
*****It's not just weapons that we get out of technology, of course. We also get creativity. A person working with an automated loom can weave vastly faster than a person without one. Spreadsheets get rid of huge amounts of manual drudgery for accountants. And with computers we take a massive leap, to the point where a single person can be a whole orchestra.
******Yes, I know about launch codes and suchlike. It's a metaphorical button - and it _could_ be a button if we wanted it to be.
Original post on Dreamwidth - there are comments there.