Neander's first tool

[Tom Bender]

Not counting the stick and the rock which were already lying around, I propose one that is humble yet still essential 'the bowl'

[mike holden]

I would suggest a second rock to knap the first into a sharp edge, thus igniting the "sharpening wars" that exist to this day (grin).

[Jim Koepke]

I would suggest a second rock to knap the first into a sharp edge, thus igniting the "sharpening wars" that exist to this day (grin).

With definite divisions over which are the best materials to knap and which are best for knapping.

jtk

[Roger Nair]

I, after rock and wood are eliminated, would expect animal products such as bone, antler, skin, gut and sinew.

[Osvaldo Cristo]

Not counting the stick and the rock which were already lying around, I propose one that is humble yet still essential 'the bowl'

Essential? A good enough Internet connection, of course! Otherwise how could you access these forums and order from amazon?

[Tom Trees]

Some planes will get you into straight into the game, as thats the first tool to touch the timber from the sawmill.
they will make you understand timber, and how unbelievably precice you can actually make things, compared to any other power tool you might have used before.
assuming you have never used a power jointer.

Depending on the wood you will be working on, i.e...
Rough sawn lumber, reclaimed and the species will play a factor in what planes you want.

I suggest getting a pair of nice vintage no. 5 1/2 Bailey pattern planes, and another cheap no.4 or two.
Best to look for ones with as thick a casting as you can find, as some people have lapped planes in an effort to improve them, and assumed the process to be foolproof
because they had a dead flat fancy surface plate of some kind, and just rubbed away until they seen a full scratch pattern ...
Just like 99.99% of folks will show on youtube.
This mindless lapping does not work , and you are better leaving the sole alone, because if you do said work, you will create a convex sole in both directions.
(no matter how skilled you are) a convex sole will be the outcome.
So look for planes that has got no work like said done to them, thick soles seen from both front and back pictures, and an even thickness..i.e not thicker on the left or right side.

I wouldn't spend more than about 30 quid for a no.4 .

Having a moderate camber on one jack, and one for smoothing is my preference
One cheap rough n ready no 4, or 5 for scrub work, and another no.4, or no.3 for smoothing small pieces.

A square or two, one of them a smaller machinists square.
A nice small diamond plate like Dia-sharp 1800 grit for the backs of the irons and whatever other stone you choose.
You might need to find a flat plate of some sort and use sandpaper, or get another rough hone that will stay flat to get the backs of your irons lapped...
A brand called Ultex makes cheap plates, what come on a half price sale annually, so for about less than 20 quid.
It would take you weeks if you tried lapping the backs with that 1800 hone, this hone is for polishing the previous scratch pattern
My preference would be to find a Washita.
A bench grinder, otherwise you stand a very good chance that you will not learn freehand sharpening.

A flat bench, or at least having a somewhat long accurate straight edge,

The bench should not move...
A composite fire door if you can find one for nothing would be handy, and you could butt it against a wall resting on sawhorses like Andrew Hunter's would be simple
if you have literally nothing.

And an angle poise work lamp
Good luck
Tom

[steven c newman]

Bow saw....can also be used as a drill (just switch from a blade to a bit)....then when it gets cold, or you need to warm up the glue pot, change to the fire-starter tip. The first Multi-tool....

[john zulu]

Survival knife......