Joel Fuhrman

On embarking to return we could perceive no sign of One Tree Island; and as we swept down towards the sea the leafy top of a tree seen in the clear water under the boat was the only evidence of its existence; though a few hours ago it had formed so prominent an object.

Well the real concept of basic needs if you cut it right down are simply the physical needs that are unavoidable for all of us. So to have enough calories to keep our bodies going. Have shelter from extreme elements. To have water that is safe to drink, So I think that's the core of it.