You've probably heard the saying "Necessity is the mother of invention" a few times. The phrase implies that necessity springs out of the blue, and that civilization ceases to function until whatever sudden pressing need has been satisfied. At best, the phrase is a tautology. At worst, it is an indication that the speaker of the phrase is the sort of simple-minded fool that spouts trite expressions without giving thought to reality.
If you were to step back and take stock of your surroundings right now, you would be hard pressed to find anything that you need that isn't somehow provided for. You aren't special -- it's like that for everybody. And everybody now isn't special, either: people who lived in the 1800s had everything they needed as well; so did the people living in prehistoric times. The technology and other "things" that exist in a given time define that era; that is to say that our tools are, by definition, adequate for living in our world, just as the tools of cavemen were adequate for living in prehistoric times. Citizens of the world didn't wake up one morning in 1923 and realize that nobody could go on living until the television was invented; they had other perfectly adequate means (such as radio or print) to distribute news and entertainment. The Wright brothers didn't realize, 100 years ago, that civilization would collapse if they weren't able to get an airplane to fly. And, heartless as it may seem, if nobody stumbled across Penicillin, there might be fewer of us around, but we'd still be here.
Some people choose to invert the phrase; they say "invention is the mother of necessity." It's a tempting thought -- first we invent the horse-drawn carriage, then we invent the automobile to replace the carriage, but to make the automobile more palatable, we must invent power steering, cruise control, leather seats, huge stereo systems, radar-assisted parking systems, etc. A more interesting example is that of the tin can. One would suspect that the invention of the tin can would necessitate the immediate invention of the can opener. But while the tin can was first presented in 1810, the first useful can opener didn't appear until nearly 50 years later. In reaction to this, the mind's eye conjures up amusing images of an entire generation of hungry Victorians starving and contemplating the bitter irony of life as they stared at shelves full of canned foods; but fortunately it wasn't so. Instead, people looked at their surroundings and used what they had. For example, a tin containing roast veal carried on the explorer William Edward Parry's Arctic expedition in 1824 included the following instructions for opening: "Cut round on the top with a chisel and hammer." Soldiers fighting in the American Civil War opened their canned rations with knives, bayonets, and even rifle fire. The earliest purpose-built can openers were cumbersome, complicated gadgets that were owned by shopkeepers, which was unfortunate because opening your cans at the checkout register defeats the purpose of having the stuff canned in the first place. William Underwood, who established America's first cannery in the 1920s, advised his customers to use whatever tools were around the house to open the cans.
As Thomas Edison wrote, "Restlessness is discontent -- and discontent is the first necessity of progress." Surely, inconvenience breeds restlessness, and it's not too hard to see that there was no convenient method for most people to open tin cans; this inconvenience was what got Ezra Warner of Waterbury, CT thinking in her spare time, and eventually led to her landmark 1858 patent for a can opener that just about anybody could use. It worked well enough, but its use left cans with sharp, jagged edges. Although a nasty cut to the finger is most often not fatal, it can be inconvenient, and in 1870, because of this, William Lyman of West Meriden, CT, patented the first can opener to use a wheel-shaped blade which made a smooth, continuous edge.
The story goes on, but perhaps you see the point I'm getting at -- necessity is not the mother of invention, and invention is not the mother of necessity. Inconvenience is the mother of invention; necessity is already provided for,
or else we wouldn't be here. I make the (bold? foolish?) claim that nothing that has ever been invented has been necessary; new items are only invented to improve upon the perceived shortcomings of existing items. Don't believe me? Look around your desk; pick up anything, and think: what need went unfulfilled before this thing was invented? What would people have ever done without it? I assure you, nothing man-made predates man, so somewhere along the line, someone got along without anything that we've invented so far. They may not have liked getting along without it, but that's why it's here today -- because it just makes life so much more convenient.