At a time when we seem most to need the comfort, congeniality, and reassurance of a cozy hearth and warm fire, more and more reasons accumulate not to have a fireplace or wood stove. These include pollution indoors and out, and backdrafting of dangerous flue gases in tightly sealed homes. Technical solutions, such as catalytic converters and glass doors, don't seem to be keeping up with the problems, so maybe we should attack them head-on. If the fireplace is outlawed and we can't snuggle up to a burning log, what can we do to focus our afterdinner get-togethers? Why Fireplaces and Stoves Appeal to Us A love of fires may well be built into human nature. Lisa Heschong, in